The Consultative Committee for Space Data Systems (CCSDS) was formed in 1982 by the major space agencies of the world to provide a forum for discussion of common problems in the development and operation of space data systems. It is currently composed of ten member agencies, twenty-two observer agencies, and over 100 industrial associates.
Since its establishment, it has been actively developing Recommendations for data- and information-systems standards to a) reduce the cost to the various agencies of performing common data functions by eliminating unjustified project-unique design and development, and b) promote interoperability and cross support among cooperating space agencies to reduce operations costs by sharing facilities.
Friday 20 July 2007
The Bridge Between Research and Operations
Dave Jones
Stanley R. Schneider
Peter Wilczynski
Craig Nelson
This is the third in a series of articles on the National Polar-orbiting Operational Environmental Satellite System (NPOESS). This month we review the NPOESS Preparatory Project (NPP) that will be flown as a precursor to POESS. NPP is the “Bridge” to span the transition and reduce risk as the program moves from NASA research to NOAA and DoD operations.
Introduction
More than 40 years after the launch of the first weather satellite in April 1960, the United States is changing the way that environmental satellites are acquired, managed, and operated. Weather forecasters, scientists, and decision-makers are counting on the future converged weather satellite system, the National Polar-orbiting Operational Environmental Satellite System (NPOESS), to meet their needs for Earth science data and information in the 21st Century. NPOESS marks the transition from a time when polar-orbiting weather satellites were operated by two separate government agencies with separate missions to a modern cost-effective, single operational environmental satellite system providing global, simultaneous observation of the Earth system. NPOESS builds on research and technology development by the National Aeronautics and Space Administration (NASA) and will be operated by the National Oceanic and Atmospheric Administration (NOAA) and the Department of Defense (DoD) through an integrated program office.
To ensure that the research to operations transition is successful and that the best technology and instrument concepts meet both weather and climate needs, NASA and the tri-agency NPOESS Integrated Program Office (IPO) have partnered on the NPOESS Preparatory Project (NPP). NPP is a unique satellite mission scheduled for launch in October 2006 as a precursor to NPOESS. NPP serves the complementary research objectives of NASA and the pre-operational test objectives of the IPO. For NASA, NPP ensures continuity of many of the critical climate data sets begun with the launch of NASA’s Earth Observing System (EOS) Terra satellite in 1999. For the IPO, NPP provides risk reduction for four critical sensors that will be flown operationally on NPOESS several years later and for the associated algorithms which convert the sensor measurements into environmental data products. NPP also serves as an early test of the NPOESS ground segments—command, control & communications, and data processing and will provide access to data from the next generation of operational sensors for early evaluation by users. Early access and evaluation will ensure that data from NPOESS will be incorporated into NOAA and DoD operations soon after its availability.
Partnerships Pave the Way
NASA and NOAA have collaborated on the development and operation of weather satellites in one of the most effective and beneficial partnerships in the United States government for more than 40 years. That partnership continues with NPP.
Due to the importance of NPOESS to the military and civilian communities, the partnering agencies in the IPO were directed to undertake a robust risk reduction effort to help ensure success of the program. Laboratory, airborne, and Space Shuttle-based efforts were considered and incorporated into the risk reduction plan. The most desirable approach was to actually test some of the NPOESS developmental sensors on-orbit in a quasi-operational environment. The IPO looked at the feasibility of flying some of the NPOESS sensors on the last of the DoD Defense Meteorological Satellite Program (DMSP) and NOAA Polar-orbiting Operational Environmental Satellite (POES) spacecraft, but available space for additional instruments, restricted fields of view, limited onboard data systems, and costs were prohibitive for these 1970s era satellites.
The NASA Earth Observing System satellites were designed to further the study of the Earth’s systems and their interactions, including global climate change, through the systematic study of terrestrial, oceanic, biospheric, and atmospheric phenomena from a variety of space borne platforms. EOS Terra was launched in December 1999 to focus on land and ocean surface measurements; EOS Aqua was launched in May 2002 to improve understanding and prediction of the hydrologic cycle; and EOS Aura is scheduled for launch in June 2004 to study the Earth’s ozone, air quality, and climate. Originally, NASA planned for two successor flights for each of these 6-year missions for a total of 18 years of coverage. However, the program took a new direction in 1998 that led to a strategy of careful analysis of the data from the first round of EOS missions before deciding which data sets needed to be continued.
Renewed emphasis was put on partnering to transition these research data sets to sustained monitoring programs within operational agencies. This culminated in the NPOESS Preparatory Project, the joint mission with the IPO to carry forward selected EOS measurements while meeting the NPOESS risk reduction goals.
Dr. Ghassem Asrar, NASA’s Associate Administrator for Earth Science says, “NPP represents an exciting opportunity for NASA and NOAA to combine their organization’s strengths for the advancement of both science and operational needs. NPP and NPOESS capitalize on NASA’s observational breakthroughs with Terra and Aqua, and NOAA and DoD’s sustained operational capabilities with POES and DMSP, thus providing long-term, critical observations for understanding climate change mechanisms as well as weather.”
The NPP program is jointly managed by the IPO and NASA while responsibilities for the mission are shared between the parties. NASA is responsible for:
n Mission systems engineering;
n Integration, and test;
n Development of the Advanced Technology Microwave Sounder (ATMS) instrument;
n Spacecraft and integration;
n Launch vehicle and associated activities;
n Science Data Segment (SDS).
The IPO, together with the NPOESS prime contractor, Northrop Grumman Space Technology (NGST), is responsible for:
n Visible/Infrared Imager Radiometer Suite (VIIRS);
n Cross-track Infrared Sounder (CrIS);
n Ozone Mapping and Profiler Suite (OMPS);
n Command, Control, and Communications Segment (C3S);
n Interface Data Processing Segment (IDPS);
n NPP mission operations.
NOAA’s National Environmental Satellite, Data, and Information Service (NESDIS) is responsible for:
n Archive and Distribution Segment (ADS).
The ADS will provide users access to near real-time and archived data from NPP.
Continuity of Data: The Basis for Climate Research
Remote sensing of the planet has generated science records that now represent decades of continuous observations of the atmosphere, oceans, and land. Much like a medical record in human health care, this Earth “record” is essential to assemble and understand the long-term history of the planet and its dynamic climate.
NPP will play a significant role in continuing and maintaining the long-term Earth environmental data record into the NPOESS era. NPP will be in orbit in advance of the expected end-of-life of EOS Aqua (~2008), and should provide significant overlap with the first NPOESS spacecraft. NPP will be an effective “bridge” between the Terra and Aqua EOS missions and NPOESS with numerous opportunities for cross-calibration and validation among existing sensors and the advanced instrumentation for NPOESS.
For climate researchers, NPP and NPOESS will be the sources for much of the satellite-derived climate data in the future. Selected near real-time Environmental Data Records (EDRs) from NPP and NPOESS will form the basis of Climate Data Records (CDRs). The quality of these EDRs for climate research will be validated during the NPP mission by NASA’s Science Data Segment (SDS).
NASA’s goal, through partnership with the IPO, is to maintain the space-based climate record by having research-quality measurements on operational environmental satellites. In the long-term, beyond the EOS Terra and Aqua missions, NASA will rely on NPOESS for systematic global mapping of the Earth’s surface at moderate resolution. NOAA initiatives for use of NPP and NPOESS data for climate monitoring will be the subject of a forthcoming article in this series.
NPP Keystone Sensors
and Systems
The four instruments selected for flight on the NPP spacecraft trace their heritage to NASA instruments on EOS Terra, Aqua, and Aura, but push the technology envelope even further. The following sensors are designed to perform imaging, atmospheric sounding, and ozone monitoring functions and are identified below:
VIIRS—Visible/Infrared Imager Radiometer Suite
The VIIRS imager on NPP is the follow-on instrument to the imagers on DoD’s DMSP, NOAA’s POES, and the EOS Terra and Aqua satellites. The constant resolution Operational Linescan System (OLS) imager on the DMSP satellite contains only three channels; visible, infrared, and a day/night band. The day/night channel detects low levels of visible-near infrared radiance at night from sources on the Earth’s surface, including clouds illuminated by moonlight. Detection of these types of features can be critically important for military operations. The OLS can also detect lights from cities, towns, industrial sites, gas flares, heavily lit fishing boats, and fires. This low-light capability will be carried forward to VIIRS on NPP and NPOESS, but at a much higher horizontal resolution than is currently available.
The VIIRS (being developed by Raytheon’s Santa Barbara Remote Sensing (SBRS) Group, the same company that manufactured the Moderate Resolution Imaging Spectroradiometer (MODIS) that is on EOS Terra and Aqua) will fly on NPP as well as on all NPOESS platforms. VIIRS will provide complete global coverage in one day over the visible, short, mid-, and long-wave infrared regions at horizontal spatial resolutions of 370m at nadir. In addition, VIIRS will image at a near constant horizontal resolution across its ~3000 km swath, a significant improvement over the Advanced Very High Resolution Radiometer (AVHRR—on POES) and MODIS instruments. VIIRS will produce environmental data such as sea ice, sea surface temperature, ocean color, aerosols, albedo, cloud parameters, vegetation, and surface type.
CrIS & ATMS—Atmospheric Sounders
The atmospheric sounders on NPP consist of the CrIS (Cross-track Infrared Sounder) and the ATMS (Advanced Technology Microwave Sounder). Together these make up the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The suite will be used to provide vertical profiles of atmospheric temperature, humidity, and pressure from the surface to the top of the atmosphere. The CrIS, a Michelson Interferometer-based sensor, is being developed by ITT Aerospace of Fort Wayne, Indiana. CrIS will succeed the Atmospheric Infrared Sounder (AIRS) which operates on EOS Aqua and the operational High Resolution Infrared Sounder (HIRS) on POES. As the follow-on instrument to AIRS, CrIS is designed to provide vertical temperature profiles at 1° K accuracy for 1 km layers in the troposphere, a standard currently being achieved by AIRS globally and approximating the accuracy of the data obtained from radiosondes, which are carried aloft by weather balloons. Radiosondes collect critical weather information through many atmospheric layers and are what world-wide weather services have traditionally used to initialize their weather forecast models.
The ATMS is a 22-channel passive microwave sensor that will scan synergistically with CrIS and provide soundings even in the presence of clouds. The ATMS is being built by Northrop Grumman Electronic Systems (NGES) in Azusa, California as the successor to the Advanced Microwave Sounding Units (AMSU which have flown on NOAA satellites since the mid- 1990s and are currently aboard EOS Aqua. By using state-of the-art technologies, the functionality of three AMSU units (AMSU- A1, A2, and Microwave Humidity Sounder-MHS) will be compressed into a single unit with a payload mass savings of 100 kilograms.
Ozone Mapping & Profiler Suite
The Ozone Mapping and Profiler Suite (OMPS) on NPP consists of two sensors; a nadir pointing scanner that will be used to obtain measurements of the total column ozone and a limb scanner which looks past the forward edge of the spacecraft to obtain vertical profiles of ozone in the Earth’s stratosphere. Both units operate in the ultraviolet (UV) portion of the spectrum. The OMPS is being developed by Ball Aerospace and Technologies Corporation in Broomfield, Colorado, the same company that built the Solar Backscatter Ultraviolet Radiometer 2 (SBUV/2) instrument that is on the NOAA POES. Heritage for the nadir total column scanner goes back to the Total Ozone Mapping Spectrometer (TOMS), which first flew on Nimbus-7 in 1978 and has been flown three more times since then, as well as to the Ozone Monitoring Instrument (OMI) that will fly on EOS Aura in June 2004. The TOMS has been used to identify and monitor the changes in the ozone hole over Antarctica. The technology for the limb-profiling unit is derived from the Shuttle Ozone Limb Scanning Experiment (SOLSE) that flew on NASA’s Space Shuttle missions STS-87 in 1997 and STS-107 which was lost tragically on February 1, 2003. The UV limb scanner is intended to provide vertical profiles of ozone concentrations for 3 to 5 km thicknesses of the atmosphere as compared to the 7 to 10 km thicknesses obtained from the SBUV/2 on NOAA POES. Data collected by OMPS will help fulfill U.S. treaty obligations under the Montreal Protocol to monitor ozone depletion in the atmosphere and determine if synthetic chemicals are affecting the Earth’s climate and its habitability.
NPP Spacecraft
The NPP spacecraft being developed by Ball Aerospace under contract to NASA is a variation of Ball’s commercial spacecraft design used by NASA in prior Earth Science missions such as QuikSCAT (Quick Scatterometer) and ICESat (Ice, Cloud, and Land Elevation Satellite). The launch is planned for October 2006 from Vandenburg Air Force Base, California. A Delta II launch vehicle will be used to inject NPP into an 824 km, sun-synchronous polar orbit with a 1030 AM descending equatorial nodal crossing time. The mid-morning crossing time was chosen to take advantage of minimum cloud cover over land surfaces. Although average cloudiness in the mid-morning differs little from the mid-afternoon, there tend to be almost twice as many days with less than 10 percent cloud cover in the mid-morning than mid-afternoon. The expected mission duration for NPP is five years with 7.5 years of consumables (i.e., fuel for orbital station keeping of +/-10 minutes of equatorial nodal crossing time).
The satellite will be commanded from the NPP-NPOESS Mission Management Center (MMC) in Suitland, Maryland. The MMC is the heart of the NPOESS Command, Control and Communications Segment (C3S), developed by Raytheon Space Systems in Aurora, Colorado.
Global, or stored mission, data will be down-linked at X-band frequencies (8212.5 MHz) to a 13-meter ground receiving antenna located at Svalbard, Norway. Unlike the SafetyNet communications network that will acquire NPOESS data, NPP will have only one data receiving station at Svalbard which is located at high enough latitude (78 degrees north) to be able to “see” all 14 daily NPP satellite passes. Real-time data will also be broadcast on a continuous basis via an X-band (7750-7850 MHz) High Rate Data (HRD) link. Anyone with a ground station designed to receive and process NPP data will be able to do so when the satellite comes into range of the receiving antenna.
The global data will be transmitted from Svalbard within minutes to the U.S. via a fiber-optic cable system that was completed in January 2004 as a joint venture between the IPO, NASA, and the Norwegian Space Centre. NPP will generate approximately 1.5 terabytes of data per day, which is similar to the current data volumes from EOS Terra and Aqua. The four sensors on NPP will provide 80 percent of the data rate assigned to all fourteen sensors on NPOESS. This will be a significant step toward completing the data handling processes needed to accommodate even more data when NPOESS comes online.
NPP’s four sensors will also provide 25 of the 55 NPOESS Environmental Data Records (EDRs). Once the data stream is in the U.S., the Raw Data Records (RDRs) will be processed into Sensor Data Records (SDRs) and EDRs by the Interface Data Processing Segment (IDPS), also being developed by Raytheon Space Systems in Aurora, Colorado. Raw Data Records (Level 0/1A) will be full resolution, unprocessed sensor data, time-referenced, with earth location, radiometric and geometric calibration coefficients appended, but not applied, to the data. Sensor Data Records (Level 1B) will be full resolution sensor data that are time referenced, earth located, and calibrated. Environmental Data Records (Level 2) are fully processed sensor data that contain the geophysical parameters or imagery that must be generated as user products. All three levels of data records (RDRs, SDRs, and EDRs) will be available to users.
Two IDPS systems will be installed to support NPP at operational weather facilities (Centrals): NOAA’s NESDIS in Suitland, Maryland for processing and distribution of data to civilian organizations; and the Air Force Weather Agency (AFWA) in Omaha, Nebraska to support the military. By the time the first NPOESS is available for launch in late 2009, IDPS systems will also be located at U.S. Navy facilities in Monterey, California and at Stennis Space Center in Bay St. Louis, Mississippi. All records from NPP will be archived by NOAA from which access can be obtained by other agencies and the public.
Calibration/Validation:
Solid Support for Science
NPP has already passed important milestones on its path to the launch pad. This includes a Critical Design Review in October 2003 for the systems and the overall mission and a successful Mission Confirmation Review in the fall of 2003 that moved NPP into the implementation phase. A calibration/validation plan for NPP has been drafted and selected “ground-truth” assets, such as the NPOESS Airborne Sounder Testbed, are already deployed. A NASA NPP Science Team was competitively selected in September 2003 and had their inaugural meeting in November 2003. As the “bridge” between EOS and NPOESS, NPP will provide “lessons learned” and allow for any required modifications to hardware systems or algorithms in time to support readiness for the first NPOESS launch.
Continuity of data from EOS to NPOESS will require calibration of the NPP instruments and validation of algorithms following EOS-type approaches and cross-calibration of these instruments on-orbit with the corresponding EOS instruments (e.g., VIIRS and MODIS; CrIS and AIRS; ATMS and AMSU/MHS). NPP will allow scientists to develop, evaluate, and modify NPOESS algorithms using data collected by actual sensors on orbit instead of having to approximate data through synthetic generation, as is usually done for new sensors.
To facilitate these sensor calibration and algorithm validation efforts, certain “ground-truthing” activities have been initiated for programs such as EOS (e.g., MODIS) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). For example, in the area of ocean color, these activities include the Marine Optical Buoy (MOBY), coastal and island site augmentations of the Aerosol Robotic Network (AERONET), calibration round-robins, bio-optical and atmospheric field data archives, and development and evaluation of in situ measurement protocols. Experience gained during these programs has demonstrated that such calibration activities for NPP and NPOESS will be essential for establishing algorithms that meet science accuracy requirements; for conducting pre-launch sensor characterization and post-launch validation; and to evaluate on-orbit sensor performance.
Taking Research into Battle
A primary mission of NPP is to test and deliver high resolution imaging and sounding data to operational users so that they can familiarize themselves with the new capabilities and prepare for NPOESS. The IDPS system at NESDIS will deliver more accurate and timely data for use in NOAA’s numerical weather prediction models that support a wide variety of civil applications. A second IDPS system at the Air Force Weather Agency is intended to provide direct support for military operations. But the military is not waiting for the arrival of NPP to realize the benefits of advanced remote-sensing technologies. For example, the Naval Research Laboratory in Monterey, California has already processed MODIS data from NASA’s EOS Terra and Aqua satellites. The data provided time-critical information about sandstorms and water clarity to U.S. forces operating in the Persian Gulf, Arabian Sea, and Indian Ocean. This cooperation came about due to the work done by the IPO, NOAA, NASA, and the DoD in planning for NPP.
Despite the technological sophistication of today’s “smart” weapons and support systems, all are impacted directly or indirectly by weather and environmental situations. The data from NPP and NPOESS will help shift the tactical and strategic focus from “coping with weather” to “anticipating and exploiting” atmospheric and space environmental conditions for worldwide military advantage. For the warfighter, this should translate into more reliable long-term planning, more efficient selection and use or performance of weapon systems which are sensitive to weather, fewer aborted sorties, reduced munitions expended and, most importantly, reduced casualties. The improved capabilities from NPOESS for weather “intelligence” will be explored further in the next issue.
NPP will provide significant risk reduction to the NPOESS mission, important data continuity to NASA’s and NOAA’s climate mission, and accelerate the delivery of improved data from advanced technologies to users while facilitating user preparation for the NPOESS era.
For more information about NPP visit these two websites: www.npoess. noaa.gov and http://jointmission.gsfc. nasa.gov/.
About the Authors
Dave Jones is Founder, President and CEO of StormCenter Communications, Inc. He is also President of the ESIP Federation (esipfed.org) and Chairman of the Board for the Foundation for Earth Science. He can be reached at: dave@stormcenter.com.
Stanley R. Schneider is the Associate Director for Technology Transition and Senior NASA official at the NPOESS Integrated Program Office (IPO) and can be reached at: Stanley.Schneider@noaa. gov.
Peter Wilczynski is the NPP Program Manager at the NPOESS IPO and can be reached at: Peter.Wilczynski@ noaa.gov.
Craig Nelson is the former Executive Director of the NPOESS Integrated Program Office and can be reached at: Craig.Nelson@noaa.gov.
Stanley R. Schneider
Peter Wilczynski
Craig Nelson
This is the third in a series of articles on the National Polar-orbiting Operational Environmental Satellite System (NPOESS). This month we review the NPOESS Preparatory Project (NPP) that will be flown as a precursor to POESS. NPP is the “Bridge” to span the transition and reduce risk as the program moves from NASA research to NOAA and DoD operations.
Introduction
More than 40 years after the launch of the first weather satellite in April 1960, the United States is changing the way that environmental satellites are acquired, managed, and operated. Weather forecasters, scientists, and decision-makers are counting on the future converged weather satellite system, the National Polar-orbiting Operational Environmental Satellite System (NPOESS), to meet their needs for Earth science data and information in the 21st Century. NPOESS marks the transition from a time when polar-orbiting weather satellites were operated by two separate government agencies with separate missions to a modern cost-effective, single operational environmental satellite system providing global, simultaneous observation of the Earth system. NPOESS builds on research and technology development by the National Aeronautics and Space Administration (NASA) and will be operated by the National Oceanic and Atmospheric Administration (NOAA) and the Department of Defense (DoD) through an integrated program office.
To ensure that the research to operations transition is successful and that the best technology and instrument concepts meet both weather and climate needs, NASA and the tri-agency NPOESS Integrated Program Office (IPO) have partnered on the NPOESS Preparatory Project (NPP). NPP is a unique satellite mission scheduled for launch in October 2006 as a precursor to NPOESS. NPP serves the complementary research objectives of NASA and the pre-operational test objectives of the IPO. For NASA, NPP ensures continuity of many of the critical climate data sets begun with the launch of NASA’s Earth Observing System (EOS) Terra satellite in 1999. For the IPO, NPP provides risk reduction for four critical sensors that will be flown operationally on NPOESS several years later and for the associated algorithms which convert the sensor measurements into environmental data products. NPP also serves as an early test of the NPOESS ground segments—command, control & communications, and data processing and will provide access to data from the next generation of operational sensors for early evaluation by users. Early access and evaluation will ensure that data from NPOESS will be incorporated into NOAA and DoD operations soon after its availability.
Partnerships Pave the Way
NASA and NOAA have collaborated on the development and operation of weather satellites in one of the most effective and beneficial partnerships in the United States government for more than 40 years. That partnership continues with NPP.
Due to the importance of NPOESS to the military and civilian communities, the partnering agencies in the IPO were directed to undertake a robust risk reduction effort to help ensure success of the program. Laboratory, airborne, and Space Shuttle-based efforts were considered and incorporated into the risk reduction plan. The most desirable approach was to actually test some of the NPOESS developmental sensors on-orbit in a quasi-operational environment. The IPO looked at the feasibility of flying some of the NPOESS sensors on the last of the DoD Defense Meteorological Satellite Program (DMSP) and NOAA Polar-orbiting Operational Environmental Satellite (POES) spacecraft, but available space for additional instruments, restricted fields of view, limited onboard data systems, and costs were prohibitive for these 1970s era satellites.
The NASA Earth Observing System satellites were designed to further the study of the Earth’s systems and their interactions, including global climate change, through the systematic study of terrestrial, oceanic, biospheric, and atmospheric phenomena from a variety of space borne platforms. EOS Terra was launched in December 1999 to focus on land and ocean surface measurements; EOS Aqua was launched in May 2002 to improve understanding and prediction of the hydrologic cycle; and EOS Aura is scheduled for launch in June 2004 to study the Earth’s ozone, air quality, and climate. Originally, NASA planned for two successor flights for each of these 6-year missions for a total of 18 years of coverage. However, the program took a new direction in 1998 that led to a strategy of careful analysis of the data from the first round of EOS missions before deciding which data sets needed to be continued.
Renewed emphasis was put on partnering to transition these research data sets to sustained monitoring programs within operational agencies. This culminated in the NPOESS Preparatory Project, the joint mission with the IPO to carry forward selected EOS measurements while meeting the NPOESS risk reduction goals.
Dr. Ghassem Asrar, NASA’s Associate Administrator for Earth Science says, “NPP represents an exciting opportunity for NASA and NOAA to combine their organization’s strengths for the advancement of both science and operational needs. NPP and NPOESS capitalize on NASA’s observational breakthroughs with Terra and Aqua, and NOAA and DoD’s sustained operational capabilities with POES and DMSP, thus providing long-term, critical observations for understanding climate change mechanisms as well as weather.”
The NPP program is jointly managed by the IPO and NASA while responsibilities for the mission are shared between the parties. NASA is responsible for:
n Mission systems engineering;
n Integration, and test;
n Development of the Advanced Technology Microwave Sounder (ATMS) instrument;
n Spacecraft and integration;
n Launch vehicle and associated activities;
n Science Data Segment (SDS).
The IPO, together with the NPOESS prime contractor, Northrop Grumman Space Technology (NGST), is responsible for:
n Visible/Infrared Imager Radiometer Suite (VIIRS);
n Cross-track Infrared Sounder (CrIS);
n Ozone Mapping and Profiler Suite (OMPS);
n Command, Control, and Communications Segment (C3S);
n Interface Data Processing Segment (IDPS);
n NPP mission operations.
NOAA’s National Environmental Satellite, Data, and Information Service (NESDIS) is responsible for:
n Archive and Distribution Segment (ADS).
The ADS will provide users access to near real-time and archived data from NPP.
Continuity of Data: The Basis for Climate Research
Remote sensing of the planet has generated science records that now represent decades of continuous observations of the atmosphere, oceans, and land. Much like a medical record in human health care, this Earth “record” is essential to assemble and understand the long-term history of the planet and its dynamic climate.
NPP will play a significant role in continuing and maintaining the long-term Earth environmental data record into the NPOESS era. NPP will be in orbit in advance of the expected end-of-life of EOS Aqua (~2008), and should provide significant overlap with the first NPOESS spacecraft. NPP will be an effective “bridge” between the Terra and Aqua EOS missions and NPOESS with numerous opportunities for cross-calibration and validation among existing sensors and the advanced instrumentation for NPOESS.
For climate researchers, NPP and NPOESS will be the sources for much of the satellite-derived climate data in the future. Selected near real-time Environmental Data Records (EDRs) from NPP and NPOESS will form the basis of Climate Data Records (CDRs). The quality of these EDRs for climate research will be validated during the NPP mission by NASA’s Science Data Segment (SDS).
NASA’s goal, through partnership with the IPO, is to maintain the space-based climate record by having research-quality measurements on operational environmental satellites. In the long-term, beyond the EOS Terra and Aqua missions, NASA will rely on NPOESS for systematic global mapping of the Earth’s surface at moderate resolution. NOAA initiatives for use of NPP and NPOESS data for climate monitoring will be the subject of a forthcoming article in this series.
NPP Keystone Sensors
and Systems
The four instruments selected for flight on the NPP spacecraft trace their heritage to NASA instruments on EOS Terra, Aqua, and Aura, but push the technology envelope even further. The following sensors are designed to perform imaging, atmospheric sounding, and ozone monitoring functions and are identified below:
VIIRS—Visible/Infrared Imager Radiometer Suite
The VIIRS imager on NPP is the follow-on instrument to the imagers on DoD’s DMSP, NOAA’s POES, and the EOS Terra and Aqua satellites. The constant resolution Operational Linescan System (OLS) imager on the DMSP satellite contains only three channels; visible, infrared, and a day/night band. The day/night channel detects low levels of visible-near infrared radiance at night from sources on the Earth’s surface, including clouds illuminated by moonlight. Detection of these types of features can be critically important for military operations. The OLS can also detect lights from cities, towns, industrial sites, gas flares, heavily lit fishing boats, and fires. This low-light capability will be carried forward to VIIRS on NPP and NPOESS, but at a much higher horizontal resolution than is currently available.
The VIIRS (being developed by Raytheon’s Santa Barbara Remote Sensing (SBRS) Group, the same company that manufactured the Moderate Resolution Imaging Spectroradiometer (MODIS) that is on EOS Terra and Aqua) will fly on NPP as well as on all NPOESS platforms. VIIRS will provide complete global coverage in one day over the visible, short, mid-, and long-wave infrared regions at horizontal spatial resolutions of 370m at nadir. In addition, VIIRS will image at a near constant horizontal resolution across its ~3000 km swath, a significant improvement over the Advanced Very High Resolution Radiometer (AVHRR—on POES) and MODIS instruments. VIIRS will produce environmental data such as sea ice, sea surface temperature, ocean color, aerosols, albedo, cloud parameters, vegetation, and surface type.
CrIS & ATMS—Atmospheric Sounders
The atmospheric sounders on NPP consist of the CrIS (Cross-track Infrared Sounder) and the ATMS (Advanced Technology Microwave Sounder). Together these make up the Cross-track Infrared and Microwave Sounding Suite (CrIMSS). The suite will be used to provide vertical profiles of atmospheric temperature, humidity, and pressure from the surface to the top of the atmosphere. The CrIS, a Michelson Interferometer-based sensor, is being developed by ITT Aerospace of Fort Wayne, Indiana. CrIS will succeed the Atmospheric Infrared Sounder (AIRS) which operates on EOS Aqua and the operational High Resolution Infrared Sounder (HIRS) on POES. As the follow-on instrument to AIRS, CrIS is designed to provide vertical temperature profiles at 1° K accuracy for 1 km layers in the troposphere, a standard currently being achieved by AIRS globally and approximating the accuracy of the data obtained from radiosondes, which are carried aloft by weather balloons. Radiosondes collect critical weather information through many atmospheric layers and are what world-wide weather services have traditionally used to initialize their weather forecast models.
The ATMS is a 22-channel passive microwave sensor that will scan synergistically with CrIS and provide soundings even in the presence of clouds. The ATMS is being built by Northrop Grumman Electronic Systems (NGES) in Azusa, California as the successor to the Advanced Microwave Sounding Units (AMSU which have flown on NOAA satellites since the mid- 1990s and are currently aboard EOS Aqua. By using state-of the-art technologies, the functionality of three AMSU units (AMSU- A1, A2, and Microwave Humidity Sounder-MHS) will be compressed into a single unit with a payload mass savings of 100 kilograms.
Ozone Mapping & Profiler Suite
The Ozone Mapping and Profiler Suite (OMPS) on NPP consists of two sensors; a nadir pointing scanner that will be used to obtain measurements of the total column ozone and a limb scanner which looks past the forward edge of the spacecraft to obtain vertical profiles of ozone in the Earth’s stratosphere. Both units operate in the ultraviolet (UV) portion of the spectrum. The OMPS is being developed by Ball Aerospace and Technologies Corporation in Broomfield, Colorado, the same company that built the Solar Backscatter Ultraviolet Radiometer 2 (SBUV/2) instrument that is on the NOAA POES. Heritage for the nadir total column scanner goes back to the Total Ozone Mapping Spectrometer (TOMS), which first flew on Nimbus-7 in 1978 and has been flown three more times since then, as well as to the Ozone Monitoring Instrument (OMI) that will fly on EOS Aura in June 2004. The TOMS has been used to identify and monitor the changes in the ozone hole over Antarctica. The technology for the limb-profiling unit is derived from the Shuttle Ozone Limb Scanning Experiment (SOLSE) that flew on NASA’s Space Shuttle missions STS-87 in 1997 and STS-107 which was lost tragically on February 1, 2003. The UV limb scanner is intended to provide vertical profiles of ozone concentrations for 3 to 5 km thicknesses of the atmosphere as compared to the 7 to 10 km thicknesses obtained from the SBUV/2 on NOAA POES. Data collected by OMPS will help fulfill U.S. treaty obligations under the Montreal Protocol to monitor ozone depletion in the atmosphere and determine if synthetic chemicals are affecting the Earth’s climate and its habitability.
NPP Spacecraft
The NPP spacecraft being developed by Ball Aerospace under contract to NASA is a variation of Ball’s commercial spacecraft design used by NASA in prior Earth Science missions such as QuikSCAT (Quick Scatterometer) and ICESat (Ice, Cloud, and Land Elevation Satellite). The launch is planned for October 2006 from Vandenburg Air Force Base, California. A Delta II launch vehicle will be used to inject NPP into an 824 km, sun-synchronous polar orbit with a 1030 AM descending equatorial nodal crossing time. The mid-morning crossing time was chosen to take advantage of minimum cloud cover over land surfaces. Although average cloudiness in the mid-morning differs little from the mid-afternoon, there tend to be almost twice as many days with less than 10 percent cloud cover in the mid-morning than mid-afternoon. The expected mission duration for NPP is five years with 7.5 years of consumables (i.e., fuel for orbital station keeping of +/-10 minutes of equatorial nodal crossing time).
The satellite will be commanded from the NPP-NPOESS Mission Management Center (MMC) in Suitland, Maryland. The MMC is the heart of the NPOESS Command, Control and Communications Segment (C3S), developed by Raytheon Space Systems in Aurora, Colorado.
Global, or stored mission, data will be down-linked at X-band frequencies (8212.5 MHz) to a 13-meter ground receiving antenna located at Svalbard, Norway. Unlike the SafetyNet communications network that will acquire NPOESS data, NPP will have only one data receiving station at Svalbard which is located at high enough latitude (78 degrees north) to be able to “see” all 14 daily NPP satellite passes. Real-time data will also be broadcast on a continuous basis via an X-band (7750-7850 MHz) High Rate Data (HRD) link. Anyone with a ground station designed to receive and process NPP data will be able to do so when the satellite comes into range of the receiving antenna.
The global data will be transmitted from Svalbard within minutes to the U.S. via a fiber-optic cable system that was completed in January 2004 as a joint venture between the IPO, NASA, and the Norwegian Space Centre. NPP will generate approximately 1.5 terabytes of data per day, which is similar to the current data volumes from EOS Terra and Aqua. The four sensors on NPP will provide 80 percent of the data rate assigned to all fourteen sensors on NPOESS. This will be a significant step toward completing the data handling processes needed to accommodate even more data when NPOESS comes online.
NPP’s four sensors will also provide 25 of the 55 NPOESS Environmental Data Records (EDRs). Once the data stream is in the U.S., the Raw Data Records (RDRs) will be processed into Sensor Data Records (SDRs) and EDRs by the Interface Data Processing Segment (IDPS), also being developed by Raytheon Space Systems in Aurora, Colorado. Raw Data Records (Level 0/1A) will be full resolution, unprocessed sensor data, time-referenced, with earth location, radiometric and geometric calibration coefficients appended, but not applied, to the data. Sensor Data Records (Level 1B) will be full resolution sensor data that are time referenced, earth located, and calibrated. Environmental Data Records (Level 2) are fully processed sensor data that contain the geophysical parameters or imagery that must be generated as user products. All three levels of data records (RDRs, SDRs, and EDRs) will be available to users.
Two IDPS systems will be installed to support NPP at operational weather facilities (Centrals): NOAA’s NESDIS in Suitland, Maryland for processing and distribution of data to civilian organizations; and the Air Force Weather Agency (AFWA) in Omaha, Nebraska to support the military. By the time the first NPOESS is available for launch in late 2009, IDPS systems will also be located at U.S. Navy facilities in Monterey, California and at Stennis Space Center in Bay St. Louis, Mississippi. All records from NPP will be archived by NOAA from which access can be obtained by other agencies and the public.
Calibration/Validation:
Solid Support for Science
NPP has already passed important milestones on its path to the launch pad. This includes a Critical Design Review in October 2003 for the systems and the overall mission and a successful Mission Confirmation Review in the fall of 2003 that moved NPP into the implementation phase. A calibration/validation plan for NPP has been drafted and selected “ground-truth” assets, such as the NPOESS Airborne Sounder Testbed, are already deployed. A NASA NPP Science Team was competitively selected in September 2003 and had their inaugural meeting in November 2003. As the “bridge” between EOS and NPOESS, NPP will provide “lessons learned” and allow for any required modifications to hardware systems or algorithms in time to support readiness for the first NPOESS launch.
Continuity of data from EOS to NPOESS will require calibration of the NPP instruments and validation of algorithms following EOS-type approaches and cross-calibration of these instruments on-orbit with the corresponding EOS instruments (e.g., VIIRS and MODIS; CrIS and AIRS; ATMS and AMSU/MHS). NPP will allow scientists to develop, evaluate, and modify NPOESS algorithms using data collected by actual sensors on orbit instead of having to approximate data through synthetic generation, as is usually done for new sensors.
To facilitate these sensor calibration and algorithm validation efforts, certain “ground-truthing” activities have been initiated for programs such as EOS (e.g., MODIS) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). For example, in the area of ocean color, these activities include the Marine Optical Buoy (MOBY), coastal and island site augmentations of the Aerosol Robotic Network (AERONET), calibration round-robins, bio-optical and atmospheric field data archives, and development and evaluation of in situ measurement protocols. Experience gained during these programs has demonstrated that such calibration activities for NPP and NPOESS will be essential for establishing algorithms that meet science accuracy requirements; for conducting pre-launch sensor characterization and post-launch validation; and to evaluate on-orbit sensor performance.
Taking Research into Battle
A primary mission of NPP is to test and deliver high resolution imaging and sounding data to operational users so that they can familiarize themselves with the new capabilities and prepare for NPOESS. The IDPS system at NESDIS will deliver more accurate and timely data for use in NOAA’s numerical weather prediction models that support a wide variety of civil applications. A second IDPS system at the Air Force Weather Agency is intended to provide direct support for military operations. But the military is not waiting for the arrival of NPP to realize the benefits of advanced remote-sensing technologies. For example, the Naval Research Laboratory in Monterey, California has already processed MODIS data from NASA’s EOS Terra and Aqua satellites. The data provided time-critical information about sandstorms and water clarity to U.S. forces operating in the Persian Gulf, Arabian Sea, and Indian Ocean. This cooperation came about due to the work done by the IPO, NOAA, NASA, and the DoD in planning for NPP.
Despite the technological sophistication of today’s “smart” weapons and support systems, all are impacted directly or indirectly by weather and environmental situations. The data from NPP and NPOESS will help shift the tactical and strategic focus from “coping with weather” to “anticipating and exploiting” atmospheric and space environmental conditions for worldwide military advantage. For the warfighter, this should translate into more reliable long-term planning, more efficient selection and use or performance of weapon systems which are sensitive to weather, fewer aborted sorties, reduced munitions expended and, most importantly, reduced casualties. The improved capabilities from NPOESS for weather “intelligence” will be explored further in the next issue.
NPP will provide significant risk reduction to the NPOESS mission, important data continuity to NASA’s and NOAA’s climate mission, and accelerate the delivery of improved data from advanced technologies to users while facilitating user preparation for the NPOESS era.
For more information about NPP visit these two websites: www.npoess. noaa.gov and http://jointmission.gsfc. nasa.gov/.
About the Authors
Dave Jones is Founder, President and CEO of StormCenter Communications, Inc. He is also President of the ESIP Federation (esipfed.org) and Chairman of the Board for the Foundation for Earth Science. He can be reached at: dave@stormcenter.com.
Stanley R. Schneider is the Associate Director for Technology Transition and Senior NASA official at the NPOESS Integrated Program Office (IPO) and can be reached at: Stanley.Schneider@noaa. gov.
Peter Wilczynski is the NPP Program Manager at the NPOESS IPO and can be reached at: Peter.Wilczynski@ noaa.gov.
Craig Nelson is the former Executive Director of the NPOESS Integrated Program Office and can be reached at: Craig.Nelson@noaa.gov.
Thursday 19 July 2007
SDS Ocean Peate
Introduction
The Office of Earth Science (OES) of the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) Integrated Program Office (IPO), have agreed to jointly implement a mission called the NPOESS Preparatory Project (NPP). NPP has the objectives listed below.
1.Demonstrate and validate:
a.A global imaging radiometer and a suite of two sounding instruments, associated algorithms, and data processing
b.An ozone mapping and profiling instrument, associated algorithms, and data processing
c.A NPP Command, Control and Communications Segment (C3S), an Interface Data Processing Segment (IDPS), an Archive and Distribution Segment (ADS), and a Science Data Segment (SDS).
2.Provide continuity of systematic, global, calibrated, validated and geo-located Earth science imaging radiometry, sounding observations, and ozone mapping and profiling observations for NASA Earth Science research.
This document specifies the requirements and concept of operations for the NPP Ocean PEATE (Product Evaluation and Test Element) that will be managed and developed by NASA. As defined in NASA’s NPP Level 1 Requirements (see Appendix 1), the role of the SDS is principally directed to assessment and verification of NPP product quality, where those products are identified as Raw Data Records, Sensor Data Records, and Environmental Data Records (RDRs, SDRs, and EDRs, respectively). For the Ocean products, these will be generated exclusively using data from the Visible and Infrared Imager/Radiometer suite (VIIRS). In executing its responsibilities for assessment and verification, the SDS functions will be performed principally by a distributed and interoperable architecture of Climate Analysis Research Systems (CARS).
Acquire RDRs, SDRs, and Ocean EDRs from the SDS
Assess the quality of the NPP Ocean EDRs for accomplishing NASA’s climate research requirements
Provide suggested algorithm improvements to the IDPS via the Project Science Working Group (PSWG)
Process selected data subsets in support of Evaluation and Validation activities
Support field programs and other research activities of the Ocean Science Community.
Interfaces
The NPP Ocean PEATE will support interfaces with the following facilities and organizations:
2.1SDS Data Delivery Depository (SD3) Component
The Ocean PEATE will acquire VIIRS RDRs, SDRs and Ocean EDRs from the SD3. Prior to the NPP launch, these will be either simulated data sets for algorithm testing, or test data sets from instrument or spacecraft tests. Following launch, these will be data routinely transmitted from the IDPS. All RDRs will be acquired as they are made available at the SDS interface, while selected SDRs and EDRs will be acquired on request.
2.2SDS Integration and Test System (I&TS)
The Ocean PEATE will interact with the I&TS for processing code deliveries and updates. The I&TS will provide the latest version of the operational SDR and Ocean EDR processing code to the Ocean PEATE. The PEATE will provide proposed code and algorithm updates to the I&TS.
2.3NASA NPP Characterization Support Team (NCST)
The Ocean PEATE will interact with the NCST in support of VIIRS calibration. The NCST will provide calibration LUTS for evaluation, which may utilize more recent calibration measurements than the operational LUTS provided by the IDPS. The Ocean PEATE will provide the results of calibration evaluations to the NCST.
2.4NASA VIIRS Ocean Science Team (NVOST)
The Ocean PEATE will be co-located with the NVOST leader and will be the primary facility for analyses and evaluations performed by the NVOST. The NVOST will provide deliveries of science code, proposed algorithm improvements and evaluation processing requests to the PEATE, and will serve as the primary liason between the NASA Ocean researcher community and the Ocean PEATE. The PEATE will provide operational processing code, standard SDRs and EDRs acquired from SD3, and SDRs and EDRs generated from evaluation processing, to the NVOST.
2.5Ancillary Data Providers
The Ocean PEATE will acquire ancillary data products needed for EDR processing from various providers. The current ancillary data sets consist of TOMS and TOVS ozone data and NCEP meteorological data (wind speed, atmospheric pressure and humidity). The sources and providers of ozone and meteorological data will be reviewed and revised as needed.
Requirements
The NPP Ocean PEATE will meet the following requirements.
3.1Acquire RDRs, SDRs, and Ocean EDRs from the SDS
The Ocean PEATE will require access to the Visible and Infrared Imager/Radiometer suite (VIIRS) RDRs, SDRs, and Ocean EDRs. The Ocean EDRs are Ocean Color (40.7.6) and Sea Surface Temperature (SST) 40.2.4). (The SST requirements are TBD pending a decision by NASA Headquarters.)
The Ocean PEATE will ingest the full stream of VIIRS RDRs as they are made available at the SDS interface.
The Ocean PEATE will ingest selected subsets of the SDRs and EDRs as specified by the NVOST, for assessment and validation.
The Ocean PEATE will provide storage for VIIRS RDS, SDRs and EDRs as follows:
One full-mission set of RDRs
Approximately 10% of SDRS
Two full-mission sets of Ocean EDRs.
All prelaunch test data sets.
3.2Assess the quality of the NPP Ocean EDRs for accomplishing NASA’s climate research needs.
The Ocean PEATE will support the NVOST in performing the following assessments of the Ocean EDRs:
Ground truth validation using match-ups with in situ radiometry and chlorophyll data sets
Cross-comparisons with concurrent satellite data sets (e.g., MODIS Aqua) (if possible)
Comparisons with the climatological data sets from past missions (e.g., SeaWiFS)
Assessments of internal consistency (e.g., analysis of interannual repeatability in clear-water and deep-water regions; assessments of short-term stability).
Assessments of the effectiveness of flagging and masking algorithms (e.g., clouds, glint, stray light, zenith angle limits, turbidity).
Prelaunch assessment of algorithm functionality and implementation using simulated TOA radiances in the SDR format.
In order to fully evaluate the quality of the EDRs, the Ocean PEATE will also support the NVOST in performing the following assessment of the SDRs:
Assessment of the long-term radiometric stability of the VIIRS Ocean bands
Assessments of the instrumental corrections (e.g., temperature, RVS, polarization.)
Analysis of prelaunch test results and instrument characterization data sets.
3.3Provide suggested algorithm improvements to the IDPS via the PSWG.
The Ocean PEATE will provide algorithm and software updates to the SDS I&TS, when algorithm improvements are recommended by the NVOST for the Ocean EDRs.
3.4Process selected data subsets in support of Evaluation, Validation and Algorithm improvement activities
The Ocean PEATE will provide the capability to process any desired set of VIIRS data, up to and including the full mission data set, from RDRs to Ocean EDRs. This is required in order to support the NVOST in developing and assessing algorithm improvements for the Ocean EDRs.
The Ocean PEATE will acquire the operational SDR and Ocean EDR processing software from the SDS I&TS.
The Ocean PEATE will provide the capability to process RDRs to SDRs using the operational software. This will include the capability to accept alternative LUTs, either provided by the NCST or generated locally by the NVOST.
The Ocean PEATE will provide the capability to process SDRs to Ocean EDRs using the operational Ocean algorithms, software and LUTS.
The Ocean PEATE will provide the capability to process SDRs to Ocean EDRs using the operational Ocean algorithms and software, and alternative LUTS generated locally by the NVOST. These may include, for example, vicarious gains, flag thresholds, optical properties, or aerosol models.
The Ocean PEATE will provide the capability to process SDRs to Ocean EDRs using alternative algorithms, software and LUTS provided by the NVOST, to evaluate potential algorithm improvements and additional products.
The Ocean PEATE will support cataloging, searching, ordering and distributing of all internally processed data products.
3.5Support field programs and other research activities of the Ocean Science Community. (Note: this activity will make use of NPP/VIIRS data but is not an NPP requirement nor is the funding requested from the NPP Project for this activity.)
The Ocean CARS will support the field programs of the Ocean Science Community by providing satellite overpass predictions and near real time image support.
The Ocean CARS will provide access to local data archives by the Ocean Science Community to support the assessment of alternative algorithms and non-standard data products.
Operations Concept
The Ocean PEATE operations concept is built on the highly successful Ocean Discipline Processing System (ODPS), originally developed for SeaWiFS and enhanced for MODIS. Although operational processing of standard data products is not a PEATE function, the requirements given in Section 3 map perfectly into the ODPS approach. The basic elements of this are:
An integrated, cohesive team supporting all activities, including systems, software, data processing, calibration, validation, and distribution;
Substantial reprocessing capacity, to support rapid, multiple evaluations of potential algorithm improvements;
Rapid turnaround on critical test data sets, during prelaunch testing, initial on-orbit checkout and commissioning, and significant operational changes;
Management of a local archive of in situ ocean data for vicarious calibration and validation, in the SeaWiFS Biological Archive and Storage System (SeaBASS);
Maintenance and development of a highly capable data analysis and display package, the SeaWiFS Data Analysis System (SeaDAS), utilized for in-house analysis and freely available to the public; and
Close cooperation with the scientific community in algorithm and product evaluation and in situ data collection.
The following sections summarize the activities to be performed in support of VIIRS EDR assessment at the Ocean PEATE, followed by a summary of facilities to be provided.
4.1 VIIRS Ocean EDR Assessment
Assessment of a satellite-based ocean color sensor, such as VIIRS, should be both global and regional in scope. It commences well before launch, with the analysis of instrument test data sets and the verification of algorithms, software and procedures using simulated data. It must be a continuing process throughout the life of a satellite mission, particularly if the data products are to be used in a long-term, multi-sensor time series. For VIIRS, continuous validation is necessary for the assessment of the accuracy of the calibration across platforms.
4.1.1VIIRS Data Acquisition and Management
The complete set of VIIRS RDRs will be acquired as made available from the SD3. The timeliness of these data is critical for support of prelaunch test data evaluation, initial postlaunch instrument checkout, and field programs (see below). Selected SDRs and EDRs will be acquired as needed for calibration and data product assessment. The fraction of data to be acquired is still TBD. The facilities for storing and managing the acquired data are described in Section 4.2.
4.1.2Prelaunch and Early Mission Testing and Verification
The Ocean PEATE will support several critical activities during the prelaunch phase of NPP. These include: verification of the science algorithm and operational processing code; evaluation of test versions of the EDRs, produced by the IDPS from simulated data and transmitted to the SD3; and quick-response processing of instrument test data sets, as soon as they are acquired from the SD3.
The processing code will be acquired and installed in the ODPS to support verification and testing. The initial versions are expected to be the science algorithm code, which will be obtained by the NVOST and provided to the PEATE. As operational software becomes available on the I&TS, it will be acquired directly by the PEATE. The prelaunch versions of the software will be tested and verified using simulated data sets, either SDRs or RDRs. In order to fully exercise the logic of the Ocean EDR algorithms, high-fidelity simulated data with realistic radiances over water and clouds and geographically correct land pixels will be required.
These same data sets, along with sample EDRs produced by IDPS, will also be used to test the EDR evaluation procedures to be used during the mission. The types of evaluations to be performed are described in other sections, below.
Finally, these capabilities in the PEATE will be used to acquire and process the prelaunch instrument test data sets for analysis by the NVOST. The test data sets will be acquired from the SD3 as they become available, immediately processed as needed (i.e., RDR to SDR) and made available to the NVOST. This quick turnaround will be absolutely critical during instrument testing, to allow feedback from the NVOST to the VIIRS test team while the tests are still in progress. By analyzing test results during the actual testing, the NVOST will determine whether tests need to be rerun, either in original or modified form, to achieve the required instrument characterization result.
4.1.3 Evaluation Processing
To evaluate the efficacy of changes to the VIIRS SDR processing and the cross-calibration with MODIS/Aqua, we will develop the capability to process VIIRS RDRs, in the ODPS to produce level-2 water-leaving radiance and chlorophyll EDRs. We will use this capability to process limited amounts of VIIRS data for in situ validation, and larger amounts of VIIRS data for global, long time-series analyses. This will enable evaluation of multiple versions of the VIIRS mission data, similar to that which was performed for all SeaWiFS and MODIS reprocessings..
4.1.4 Global and Regional Comparative Time Series Analyses
We will perform global and regional comparative time-series analysis between VIIRS and MODIS/Aqua standard, archived level-3 products, and repeat the entire analysis following any VIIRS reprocessings. For periods beyond the life of the Aqua mission, we will perform clear-water and deep-water mission trend analyses. This work will establish the interannual consistency of the VIIRS radiometry.
4.1.5 In situ Matchup Comparison
The ODPS has already developed an automated system for validation of MODIS, SeaWiFS, and other sensors against the SeaBASS in situ radiance, chlorophyll and aerosol optical thickness (AOT) holdings. We will perform the in situ validation of the standard VIIRS Ocean EDRs, extending the analysis as additional VIIRS data or in situ data becomes available, and regenerating the match-up comparison following any VIIRS reprocessing. The methodology for performing the validation of VIIRS is consistent with that which we have developed and successfully applied to SeaWiFS and MODIS. Using a consistent methodology across missions and platforms will aid in developing a consistent long-term, multimission, ocean color data set.
4.1.6 Scientific Community Involvement
The SeaWiFS and SIMBIOS Projects maintained an outstanding record of involvement by the scientific community. From the first major SeaWiFS Project review in 1992, through the fourth reprocessing (Feldman and Patt, 2003), all SeaWiFS activity was conducted so as to maximize opportunities for scientific input, evaluation, and commentary by the community. This has included continual posting of the latest Project plans, analysis results, and evaluation products on the Web, and holding workshops to facilitate the exchange of ideas. The SIMBIOS Project maintained this philosophy from its inception in 1996 through 2003, with regular team meetings and wide dissemination of data and results. This approach was initiated for the MODIS Ocean team in 2004 with the selection of the new MODIS Science team.
We propose to follow this approach for our VIIRS Ocean calibration and validation activity. We will hold workshops at NASA GSFC, which will be open to all interested members of the community. These will follow the same general format as previously used for the SeaWiFS workshops and the SIMBIOS and MODIS team meetings.
We will maintain a public Web site for all of our VIIRS activities. This will include results and proceedings of the workshops; descriptions of proposed algorithm changes and calibration methodologies; results of data analyses, processing tests and product evaluations; and sample products for outside evaluation.
4.1.7 Near Real-Time Field Support
For calibration and validation purposes, in situ measurements should be made as close as possible to the sensor overflight time. The SIMBIOS Project offered overflight prediction services for MODIS (Terra and Aqua), as well as SeaWiFS and other sensors. We will continue this service and implement the capability to provide near real-time images from VIIRS level-1 and level-2 data, as is currently being done with SeaWiFS and MODIS data. These images provide useful information in oceanographic cruise planning, both prior to and during cruises. The ability to perform near-real-time image support with VIIRS will be limited by the turn-around time between observation and availability of the VIIRS RDRs.
4.1.8 SeaBASS Maintainance
Validation of remotely-sensed ocean color data is essential for determining how well the satellite-derived values reflect true conditions. This is best achieved through a comparison of coincidentally measured satellite and in situ observations, collected under the widest possible range of conditions. A comprehensive, spatially and temporally diverse in situ data set with measurements covering a wide range of oceanographic conditions is essential for such an effort. The SeaBASS database developed by the SeaWiFS and SIMBIOS Projects was designed with this goal in mind (Hooker et al., 1994; Werdell and Bailey, 2002). The in situ data archived in SeaBASS and used for validation purposes were collected using a consistent protocols (Mueller et al., 2002) and processed using a well-defined quality control procedures, as recommended by Hooker et al. (2001). We will continue the maintenance of the SeaBASS archive, soliciting voluntary contributions from the ocean color community at large to ensure the widest possible geographic and oceanographic coverage.
4.1.9 SeaDAS VIIRS Processing
We will integrate, within the current SeaDAS infrastructure, the capability to process VIIRS data to EDRs. There has been a need in the user community to be able to process data for the purposes of algorithm testing, regional and high latitude processing. Integrating VIIRS processing into SeaDAS would fill this need, without requiring a massive investment in systems and resources. It would also allow the users the flexibility to download RDR files, which can then be processed to any level, and reprocessed as soon as new calibration or software updates become available. As the MODIS/Aqua mission nears the end of its lifespan, researchers will have to make the transition to working with VIIRS data. Most of these users are already using SeaDAS and IDL, so the integration of VIIRS processing into SeaDAS would make this transition much easier for the ocean color community. Furthermore, both existing and new ocean color researches will benefit from the continuation of the well-established user support provided by the SeaDAS group.
4.2 Systems and Facilities
The systems and facilities of Code 970.2 Ocean Color Group provide the optimal environment to perform the assessment of NPP VIIRS Ocean data. By using an existing infrastructure developed specifically for this type of work, NASA will receive the maximum benefit for a minimum of cost. The group has significant network, processing, storage and software resources, in addition to its demonstrated expertise in characterizing a wide range of ocean color instruments. Using MODIS and SeaBASS data as a reference to validate the VIIRS data will require access to a large amount of data on a regular basis. Adding functionality to SeaDAS to support VIIRS data requires direct access to the developers and maintainers of SeaDAS. The facility is co-located with the ODPS, the SeaBASS archive, and the SeaDAS development team. In addition to access to data and staff, the group has access to the ODPS computing resources. The ODPS is a high-capacity, production-proven system that has been providing high-quality science products to the ocean color community daily for nearly 7 years. Data, software, and processing capabilities from that effort will be applied to a VIIRS EDR assessment effort.
4.2.1 Data Acquisition and Distribution
The systems are currently sized to acquire/process/archive and distribute SeaWiFS and MODIS data (Terra and Aqua) on a daily basis through both access the the near real-time data flow via the EDOS/NOAA bent pipe data feed and a data subscription with the Goddard DAAC. The data is sent to our dedicated file server via Goddard's high performance Science and Engineering Network (SEN). Data travels from Building 32 to Building 28 over the campus ATM backbone at 622 megabits per second, giving ample throughput to acquire the large data sets generated by MODIS. The file server receives data through its gigabit Ethernet interface, preventing bottlenecks at the destination. The connection to the SEN provides access to Internet2, a 2 gigabit per second network that can be used for collaboration and data transfer to other Internet2-connected sites. Available bandwidth for MODIS data transfers is maximized by routing all other network activity through the GSFC CNE network. The facility's servers are connected locally via a private gigabit Ethernet network, minimizing file transfer time within the project. Analyst workstations communicate via Fast Ethernet. Mechanisms for sharing data with the scientific community are already in place, requiring no additional expenditures or set-up time. The facility includes dedicated web, FTP, and mail servers. The long-established "ocean-color" mailing list is hosted there and has become a significant source for distributing ocean color information to researchers around the world.
4.2.2 Development
Software development for calibration and validation in a production environment requires a wide range of tools to be successful and easily maintained. The facility already has a rich programming environment in place, supporting development on IRIX, Linux, and Solaris. The environment includes all the necessary compilers, libraries, debuggers, and version control software. Additional development tools include IDL, Purify, GUI builders such as UIM/X and BX Pro, and SGI's ProDev development package including CaseVision and WorkShop. Maintenance contracts are in place for the commercial packages. Our group has the infrastructure, knowledge, and experience to support code development for VIIRS calibration and validation activities. Furthermore, the modular design of the ODPS system allows developers to easily add steps to the processing mix without affecting the control functions of the system.
4.2.3 Physical Facilities
The GSFC code 970.2 team has a well-supported facility located in Building 28 of Goddard's Greenbelt campus. The servers reside in a 900 square foot raised floor computer area. All the critical infrastructure required to operate a large computer facility is already in place. The room is supported by dual air conditioning systems, and has 54 KVA of UPS power to keep the servers operational 24x7. Environmental monitoring is active 24x7 as well. All hardware and software maintenance contracts are in place and kept up to date. Data security is maintained via automated backups to the backup server. The network equipment, critical to a distributed system design, is fully functional. The facility has a NASA-compliant IT security infrastructure, ensuring the safety of the data and the Project's computing resources. The systems are supported by staff located on site.
The Office of Earth Science (OES) of the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) Integrated Program Office (IPO), have agreed to jointly implement a mission called the NPOESS Preparatory Project (NPP). NPP has the objectives listed below.
1.Demonstrate and validate:
a.A global imaging radiometer and a suite of two sounding instruments, associated algorithms, and data processing
b.An ozone mapping and profiling instrument, associated algorithms, and data processing
c.A NPP Command, Control and Communications Segment (C3S), an Interface Data Processing Segment (IDPS), an Archive and Distribution Segment (ADS), and a Science Data Segment (SDS).
2.Provide continuity of systematic, global, calibrated, validated and geo-located Earth science imaging radiometry, sounding observations, and ozone mapping and profiling observations for NASA Earth Science research.
This document specifies the requirements and concept of operations for the NPP Ocean PEATE (Product Evaluation and Test Element) that will be managed and developed by NASA. As defined in NASA’s NPP Level 1 Requirements (see Appendix 1), the role of the SDS is principally directed to assessment and verification of NPP product quality, where those products are identified as Raw Data Records, Sensor Data Records, and Environmental Data Records (RDRs, SDRs, and EDRs, respectively). For the Ocean products, these will be generated exclusively using data from the Visible and Infrared Imager/Radiometer suite (VIIRS). In executing its responsibilities for assessment and verification, the SDS functions will be performed principally by a distributed and interoperable architecture of Climate Analysis Research Systems (CARS).
Acquire RDRs, SDRs, and Ocean EDRs from the SDS
Assess the quality of the NPP Ocean EDRs for accomplishing NASA’s climate research requirements
Provide suggested algorithm improvements to the IDPS via the Project Science Working Group (PSWG)
Process selected data subsets in support of Evaluation and Validation activities
Support field programs and other research activities of the Ocean Science Community.
Interfaces
The NPP Ocean PEATE will support interfaces with the following facilities and organizations:
2.1SDS Data Delivery Depository (SD3) Component
The Ocean PEATE will acquire VIIRS RDRs, SDRs and Ocean EDRs from the SD3. Prior to the NPP launch, these will be either simulated data sets for algorithm testing, or test data sets from instrument or spacecraft tests. Following launch, these will be data routinely transmitted from the IDPS. All RDRs will be acquired as they are made available at the SDS interface, while selected SDRs and EDRs will be acquired on request.
2.2SDS Integration and Test System (I&TS)
The Ocean PEATE will interact with the I&TS for processing code deliveries and updates. The I&TS will provide the latest version of the operational SDR and Ocean EDR processing code to the Ocean PEATE. The PEATE will provide proposed code and algorithm updates to the I&TS.
2.3NASA NPP Characterization Support Team (NCST)
The Ocean PEATE will interact with the NCST in support of VIIRS calibration. The NCST will provide calibration LUTS for evaluation, which may utilize more recent calibration measurements than the operational LUTS provided by the IDPS. The Ocean PEATE will provide the results of calibration evaluations to the NCST.
2.4NASA VIIRS Ocean Science Team (NVOST)
The Ocean PEATE will be co-located with the NVOST leader and will be the primary facility for analyses and evaluations performed by the NVOST. The NVOST will provide deliveries of science code, proposed algorithm improvements and evaluation processing requests to the PEATE, and will serve as the primary liason between the NASA Ocean researcher community and the Ocean PEATE. The PEATE will provide operational processing code, standard SDRs and EDRs acquired from SD3, and SDRs and EDRs generated from evaluation processing, to the NVOST.
2.5Ancillary Data Providers
The Ocean PEATE will acquire ancillary data products needed for EDR processing from various providers. The current ancillary data sets consist of TOMS and TOVS ozone data and NCEP meteorological data (wind speed, atmospheric pressure and humidity). The sources and providers of ozone and meteorological data will be reviewed and revised as needed.
Requirements
The NPP Ocean PEATE will meet the following requirements.
3.1Acquire RDRs, SDRs, and Ocean EDRs from the SDS
The Ocean PEATE will require access to the Visible and Infrared Imager/Radiometer suite (VIIRS) RDRs, SDRs, and Ocean EDRs. The Ocean EDRs are Ocean Color (40.7.6) and Sea Surface Temperature (SST) 40.2.4). (The SST requirements are TBD pending a decision by NASA Headquarters.)
The Ocean PEATE will ingest the full stream of VIIRS RDRs as they are made available at the SDS interface.
The Ocean PEATE will ingest selected subsets of the SDRs and EDRs as specified by the NVOST, for assessment and validation.
The Ocean PEATE will provide storage for VIIRS RDS, SDRs and EDRs as follows:
One full-mission set of RDRs
Approximately 10% of SDRS
Two full-mission sets of Ocean EDRs.
All prelaunch test data sets.
3.2Assess the quality of the NPP Ocean EDRs for accomplishing NASA’s climate research needs.
The Ocean PEATE will support the NVOST in performing the following assessments of the Ocean EDRs:
Ground truth validation using match-ups with in situ radiometry and chlorophyll data sets
Cross-comparisons with concurrent satellite data sets (e.g., MODIS Aqua) (if possible)
Comparisons with the climatological data sets from past missions (e.g., SeaWiFS)
Assessments of internal consistency (e.g., analysis of interannual repeatability in clear-water and deep-water regions; assessments of short-term stability).
Assessments of the effectiveness of flagging and masking algorithms (e.g., clouds, glint, stray light, zenith angle limits, turbidity).
Prelaunch assessment of algorithm functionality and implementation using simulated TOA radiances in the SDR format.
In order to fully evaluate the quality of the EDRs, the Ocean PEATE will also support the NVOST in performing the following assessment of the SDRs:
Assessment of the long-term radiometric stability of the VIIRS Ocean bands
Assessments of the instrumental corrections (e.g., temperature, RVS, polarization.)
Analysis of prelaunch test results and instrument characterization data sets.
3.3Provide suggested algorithm improvements to the IDPS via the PSWG.
The Ocean PEATE will provide algorithm and software updates to the SDS I&TS, when algorithm improvements are recommended by the NVOST for the Ocean EDRs.
3.4Process selected data subsets in support of Evaluation, Validation and Algorithm improvement activities
The Ocean PEATE will provide the capability to process any desired set of VIIRS data, up to and including the full mission data set, from RDRs to Ocean EDRs. This is required in order to support the NVOST in developing and assessing algorithm improvements for the Ocean EDRs.
The Ocean PEATE will acquire the operational SDR and Ocean EDR processing software from the SDS I&TS.
The Ocean PEATE will provide the capability to process RDRs to SDRs using the operational software. This will include the capability to accept alternative LUTs, either provided by the NCST or generated locally by the NVOST.
The Ocean PEATE will provide the capability to process SDRs to Ocean EDRs using the operational Ocean algorithms, software and LUTS.
The Ocean PEATE will provide the capability to process SDRs to Ocean EDRs using the operational Ocean algorithms and software, and alternative LUTS generated locally by the NVOST. These may include, for example, vicarious gains, flag thresholds, optical properties, or aerosol models.
The Ocean PEATE will provide the capability to process SDRs to Ocean EDRs using alternative algorithms, software and LUTS provided by the NVOST, to evaluate potential algorithm improvements and additional products.
The Ocean PEATE will support cataloging, searching, ordering and distributing of all internally processed data products.
3.5Support field programs and other research activities of the Ocean Science Community. (Note: this activity will make use of NPP/VIIRS data but is not an NPP requirement nor is the funding requested from the NPP Project for this activity.)
The Ocean CARS will support the field programs of the Ocean Science Community by providing satellite overpass predictions and near real time image support.
The Ocean CARS will provide access to local data archives by the Ocean Science Community to support the assessment of alternative algorithms and non-standard data products.
Operations Concept
The Ocean PEATE operations concept is built on the highly successful Ocean Discipline Processing System (ODPS), originally developed for SeaWiFS and enhanced for MODIS. Although operational processing of standard data products is not a PEATE function, the requirements given in Section 3 map perfectly into the ODPS approach. The basic elements of this are:
An integrated, cohesive team supporting all activities, including systems, software, data processing, calibration, validation, and distribution;
Substantial reprocessing capacity, to support rapid, multiple evaluations of potential algorithm improvements;
Rapid turnaround on critical test data sets, during prelaunch testing, initial on-orbit checkout and commissioning, and significant operational changes;
Management of a local archive of in situ ocean data for vicarious calibration and validation, in the SeaWiFS Biological Archive and Storage System (SeaBASS);
Maintenance and development of a highly capable data analysis and display package, the SeaWiFS Data Analysis System (SeaDAS), utilized for in-house analysis and freely available to the public; and
Close cooperation with the scientific community in algorithm and product evaluation and in situ data collection.
The following sections summarize the activities to be performed in support of VIIRS EDR assessment at the Ocean PEATE, followed by a summary of facilities to be provided.
4.1 VIIRS Ocean EDR Assessment
Assessment of a satellite-based ocean color sensor, such as VIIRS, should be both global and regional in scope. It commences well before launch, with the analysis of instrument test data sets and the verification of algorithms, software and procedures using simulated data. It must be a continuing process throughout the life of a satellite mission, particularly if the data products are to be used in a long-term, multi-sensor time series. For VIIRS, continuous validation is necessary for the assessment of the accuracy of the calibration across platforms.
4.1.1VIIRS Data Acquisition and Management
The complete set of VIIRS RDRs will be acquired as made available from the SD3. The timeliness of these data is critical for support of prelaunch test data evaluation, initial postlaunch instrument checkout, and field programs (see below). Selected SDRs and EDRs will be acquired as needed for calibration and data product assessment. The fraction of data to be acquired is still TBD. The facilities for storing and managing the acquired data are described in Section 4.2.
4.1.2Prelaunch and Early Mission Testing and Verification
The Ocean PEATE will support several critical activities during the prelaunch phase of NPP. These include: verification of the science algorithm and operational processing code; evaluation of test versions of the EDRs, produced by the IDPS from simulated data and transmitted to the SD3; and quick-response processing of instrument test data sets, as soon as they are acquired from the SD3.
The processing code will be acquired and installed in the ODPS to support verification and testing. The initial versions are expected to be the science algorithm code, which will be obtained by the NVOST and provided to the PEATE. As operational software becomes available on the I&TS, it will be acquired directly by the PEATE. The prelaunch versions of the software will be tested and verified using simulated data sets, either SDRs or RDRs. In order to fully exercise the logic of the Ocean EDR algorithms, high-fidelity simulated data with realistic radiances over water and clouds and geographically correct land pixels will be required.
These same data sets, along with sample EDRs produced by IDPS, will also be used to test the EDR evaluation procedures to be used during the mission. The types of evaluations to be performed are described in other sections, below.
Finally, these capabilities in the PEATE will be used to acquire and process the prelaunch instrument test data sets for analysis by the NVOST. The test data sets will be acquired from the SD3 as they become available, immediately processed as needed (i.e., RDR to SDR) and made available to the NVOST. This quick turnaround will be absolutely critical during instrument testing, to allow feedback from the NVOST to the VIIRS test team while the tests are still in progress. By analyzing test results during the actual testing, the NVOST will determine whether tests need to be rerun, either in original or modified form, to achieve the required instrument characterization result.
4.1.3 Evaluation Processing
To evaluate the efficacy of changes to the VIIRS SDR processing and the cross-calibration with MODIS/Aqua, we will develop the capability to process VIIRS RDRs, in the ODPS to produce level-2 water-leaving radiance and chlorophyll EDRs. We will use this capability to process limited amounts of VIIRS data for in situ validation, and larger amounts of VIIRS data for global, long time-series analyses. This will enable evaluation of multiple versions of the VIIRS mission data, similar to that which was performed for all SeaWiFS and MODIS reprocessings..
4.1.4 Global and Regional Comparative Time Series Analyses
We will perform global and regional comparative time-series analysis between VIIRS and MODIS/Aqua standard, archived level-3 products, and repeat the entire analysis following any VIIRS reprocessings. For periods beyond the life of the Aqua mission, we will perform clear-water and deep-water mission trend analyses. This work will establish the interannual consistency of the VIIRS radiometry.
4.1.5 In situ Matchup Comparison
The ODPS has already developed an automated system for validation of MODIS, SeaWiFS, and other sensors against the SeaBASS in situ radiance, chlorophyll and aerosol optical thickness (AOT) holdings. We will perform the in situ validation of the standard VIIRS Ocean EDRs, extending the analysis as additional VIIRS data or in situ data becomes available, and regenerating the match-up comparison following any VIIRS reprocessing. The methodology for performing the validation of VIIRS is consistent with that which we have developed and successfully applied to SeaWiFS and MODIS. Using a consistent methodology across missions and platforms will aid in developing a consistent long-term, multimission, ocean color data set.
4.1.6 Scientific Community Involvement
The SeaWiFS and SIMBIOS Projects maintained an outstanding record of involvement by the scientific community. From the first major SeaWiFS Project review in 1992, through the fourth reprocessing (Feldman and Patt, 2003), all SeaWiFS activity was conducted so as to maximize opportunities for scientific input, evaluation, and commentary by the community. This has included continual posting of the latest Project plans, analysis results, and evaluation products on the Web, and holding workshops to facilitate the exchange of ideas. The SIMBIOS Project maintained this philosophy from its inception in 1996 through 2003, with regular team meetings and wide dissemination of data and results. This approach was initiated for the MODIS Ocean team in 2004 with the selection of the new MODIS Science team.
We propose to follow this approach for our VIIRS Ocean calibration and validation activity. We will hold workshops at NASA GSFC, which will be open to all interested members of the community. These will follow the same general format as previously used for the SeaWiFS workshops and the SIMBIOS and MODIS team meetings.
We will maintain a public Web site for all of our VIIRS activities. This will include results and proceedings of the workshops; descriptions of proposed algorithm changes and calibration methodologies; results of data analyses, processing tests and product evaluations; and sample products for outside evaluation.
4.1.7 Near Real-Time Field Support
For calibration and validation purposes, in situ measurements should be made as close as possible to the sensor overflight time. The SIMBIOS Project offered overflight prediction services for MODIS (Terra and Aqua), as well as SeaWiFS and other sensors. We will continue this service and implement the capability to provide near real-time images from VIIRS level-1 and level-2 data, as is currently being done with SeaWiFS and MODIS data. These images provide useful information in oceanographic cruise planning, both prior to and during cruises. The ability to perform near-real-time image support with VIIRS will be limited by the turn-around time between observation and availability of the VIIRS RDRs.
4.1.8 SeaBASS Maintainance
Validation of remotely-sensed ocean color data is essential for determining how well the satellite-derived values reflect true conditions. This is best achieved through a comparison of coincidentally measured satellite and in situ observations, collected under the widest possible range of conditions. A comprehensive, spatially and temporally diverse in situ data set with measurements covering a wide range of oceanographic conditions is essential for such an effort. The SeaBASS database developed by the SeaWiFS and SIMBIOS Projects was designed with this goal in mind (Hooker et al., 1994; Werdell and Bailey, 2002). The in situ data archived in SeaBASS and used for validation purposes were collected using a consistent protocols (Mueller et al., 2002) and processed using a well-defined quality control procedures, as recommended by Hooker et al. (2001). We will continue the maintenance of the SeaBASS archive, soliciting voluntary contributions from the ocean color community at large to ensure the widest possible geographic and oceanographic coverage.
4.1.9 SeaDAS VIIRS Processing
We will integrate, within the current SeaDAS infrastructure, the capability to process VIIRS data to EDRs. There has been a need in the user community to be able to process data for the purposes of algorithm testing, regional and high latitude processing. Integrating VIIRS processing into SeaDAS would fill this need, without requiring a massive investment in systems and resources. It would also allow the users the flexibility to download RDR files, which can then be processed to any level, and reprocessed as soon as new calibration or software updates become available. As the MODIS/Aqua mission nears the end of its lifespan, researchers will have to make the transition to working with VIIRS data. Most of these users are already using SeaDAS and IDL, so the integration of VIIRS processing into SeaDAS would make this transition much easier for the ocean color community. Furthermore, both existing and new ocean color researches will benefit from the continuation of the well-established user support provided by the SeaDAS group.
4.2 Systems and Facilities
The systems and facilities of Code 970.2 Ocean Color Group provide the optimal environment to perform the assessment of NPP VIIRS Ocean data. By using an existing infrastructure developed specifically for this type of work, NASA will receive the maximum benefit for a minimum of cost. The group has significant network, processing, storage and software resources, in addition to its demonstrated expertise in characterizing a wide range of ocean color instruments. Using MODIS and SeaBASS data as a reference to validate the VIIRS data will require access to a large amount of data on a regular basis. Adding functionality to SeaDAS to support VIIRS data requires direct access to the developers and maintainers of SeaDAS. The facility is co-located with the ODPS, the SeaBASS archive, and the SeaDAS development team. In addition to access to data and staff, the group has access to the ODPS computing resources. The ODPS is a high-capacity, production-proven system that has been providing high-quality science products to the ocean color community daily for nearly 7 years. Data, software, and processing capabilities from that effort will be applied to a VIIRS EDR assessment effort.
4.2.1 Data Acquisition and Distribution
The systems are currently sized to acquire/process/archive and distribute SeaWiFS and MODIS data (Terra and Aqua) on a daily basis through both access the the near real-time data flow via the EDOS/NOAA bent pipe data feed and a data subscription with the Goddard DAAC. The data is sent to our dedicated file server via Goddard's high performance Science and Engineering Network (SEN). Data travels from Building 32 to Building 28 over the campus ATM backbone at 622 megabits per second, giving ample throughput to acquire the large data sets generated by MODIS. The file server receives data through its gigabit Ethernet interface, preventing bottlenecks at the destination. The connection to the SEN provides access to Internet2, a 2 gigabit per second network that can be used for collaboration and data transfer to other Internet2-connected sites. Available bandwidth for MODIS data transfers is maximized by routing all other network activity through the GSFC CNE network. The facility's servers are connected locally via a private gigabit Ethernet network, minimizing file transfer time within the project. Analyst workstations communicate via Fast Ethernet. Mechanisms for sharing data with the scientific community are already in place, requiring no additional expenditures or set-up time. The facility includes dedicated web, FTP, and mail servers. The long-established "ocean-color" mailing list is hosted there and has become a significant source for distributing ocean color information to researchers around the world.
4.2.2 Development
Software development for calibration and validation in a production environment requires a wide range of tools to be successful and easily maintained. The facility already has a rich programming environment in place, supporting development on IRIX, Linux, and Solaris. The environment includes all the necessary compilers, libraries, debuggers, and version control software. Additional development tools include IDL, Purify, GUI builders such as UIM/X and BX Pro, and SGI's ProDev development package including CaseVision and WorkShop. Maintenance contracts are in place for the commercial packages. Our group has the infrastructure, knowledge, and experience to support code development for VIIRS calibration and validation activities. Furthermore, the modular design of the ODPS system allows developers to easily add steps to the processing mix without affecting the control functions of the system.
4.2.3 Physical Facilities
The GSFC code 970.2 team has a well-supported facility located in Building 28 of Goddard's Greenbelt campus. The servers reside in a 900 square foot raised floor computer area. All the critical infrastructure required to operate a large computer facility is already in place. The room is supported by dual air conditioning systems, and has 54 KVA of UPS power to keep the servers operational 24x7. Environmental monitoring is active 24x7 as well. All hardware and software maintenance contracts are in place and kept up to date. Data security is maintained via automated backups to the backup server. The network equipment, critical to a distributed system design, is fully functional. The facility has a NASA-compliant IT security infrastructure, ensuring the safety of the data and the Project's computing resources. The systems are supported by staff located on site.
SDS LAnd Peate
Introduction
The Office of Earth Science (OES) of the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) Integrated Program Office (IPO), have agreed to jointly implement a mission called the NPOESS Preparatory Project (NPP). NPP has the objectives listed below.
1.Demonstrate and validate:
a.A global imaging radiometer and a suite of two sounding instruments, associated algorithms, and data processing
b.An ozone mapping and profiling instrument, associated algorithms, and data processing
c.A NPP Command, Control and Communications Segment (C3S), an Interface Data Processing Segment (IDPS), an Archive and Distribution Segment (ADS), and a Science Data Segment (SDS).
2.Provide continuity of systematic, global, calibrated, validated and geo-located Earth science imaging radiometry, sounding observations, and ozone mapping and profiling observations for NASA Earth Science research.
This document specifies the requirements and concept of operations for the NPP Land PEATE (Product Evaluation and Test Element) that will be managed and developed by NASA. As defined in NASA’s NPP Level 1 Requirements (see Appendix 1), the role of the SDS is principally directed to the assessment and verification of NPP product quality, where those products are identified as Raw Data Records, Sensor Data Records, and Environmental Data Records (RDRs, SDRs, and EDRs, respectively). In executing its responsibilities for assessment and verification, the following SDS functions will be performed:
Acquire RDRs, SDRs, and VIIRS Land EDRs from the SDS
Assess the quality of the VIIRS Land EDRs for accomplishing NASA’s climate research requirements
Provide suggested algorithm improvements to the IDPS via the Project Science Working Group (PSWG)
Process selected data subsets … in support of Calibration/Validation activities
Interfaces
The NPP Land PEATE will support interfaces with the following facilities and organizations:
2.1SDS Data Delivery Depository (SD3) Component
The Land PEATE will acquire all VIIRS RDRs, and selected SDRs and Land EDRs from the SD3. All RDRs will be acquired as they are made available at the SDS interface, while selected SDRs and EDRs will be acquired on request.
2.2NASA NPP Characterization Support Team (NCST)
The Land PEATE will interact with the NCST in support of VIIRS calibration including running large-scale tests of improved calibration software in the Land PEATE. The NCST will provide calibration Look-Up Tables (LUTs) for evaluation, which may utilize more recent calibration measurements than the operational LUTS provided by the IDPS. The Land PEATE will provide the results of calibration evaluations to the NCST.
2.3VIIRS Land Science Team (VLST)
The NPP Land PEATE will be co-located with members of the VLST and will be the primary facility for analyses and evaluations performed by the VLST. The VLST will provide proposed algorithm improvements and evaluation processing requests to the PEATE and serve as the primary liaison between the NASA Land research community and the NPP Land PEATE. The PEATE will provide standard SDRs and EDRs acquired from SD3, and SDRs, EDRs and Level 3 land products generated to support product evaluation and validation activities to the VLST.
2.4Ancillary Data Providers
The Land PEATE will acquire ancillary data products needed for EDR processing from various providers. The ancillary products required by VIIRS Land EDRs running in the IDPS will be documented in the Environmental Data Records Interdependency Report (D36385). The Land PEATE will also acquire additional ancillary data products identified by the VLST as required for testing improved algorithms for the generation of EDRs.
Requirements
The NPP Land PEATE will meet the following requirements.
3.1Acquire RDRs, SDRs, and Land EDRs from the SDS
The Land PEATE shall receive the all Visible and Infrared Imager/Radiometer suite (VIIRS) RDRs and SDRs and the following Land EDRs:
Albedo (Surface)
Land Surface Temperature
Vegetation Index
Snow Cover and Depth
Surface Type
Active Fires
Ice Surface Temperature
The Land PEATE shall ingest the all VIIRS RDRs as they are made available at the SD3 interface, nominally within 1 day but always within 16 days of availability.
The Land PEATE shall ingest selected subsets of the SDRs and EDRs as specified by the VLST, for assessment and validation.
The Land PEATE shall provide storage for VIIRS RDRs, SDRs and EDRs as follows:
One full-mission set of RDRs (i.e. one year of RDRs for each year of the mission).
120 data-days of SDRs
Two full-mission sets (i.e. two 1 year sets of EDRs, an improved and a baseline set, for each year of the mission) of Land EDRs.
An additional 25% margin in storage capacity will be provided as requested by the NPP System Engineer upon receipt of additional funding from the NPP Project.
3.2Assess the quality of the NPP Land EDRs for accomplishing NASA’s climate research needs.
The Land PEATE shall support the NVLST in performing the following assessments of the Land EDRs:
a.Ground truth validation using satellite observations acquired over land validation sites and in-situ data acquired by instrumentation at the sites.
b.Cross-comparisons with concurrent satellite data sets (e.g., MODIS)
c.Comparisons with the long-term data sets from past missions (e.g., AVHRR)
d.Assessments of product in terms of internal consistency and expected trends over time (time series analysis of seasonal variability and outlier identification).
e.Assessments of the effectiveness of masking algorithms (e.g., clouds, land/water boundaries)
f.Pre-launch assessment of algorithm functionality and implementation using simulated TOA radiances in the SDR format.
g.Assessments of the impact of algorithm changes on products downstream in the processing chain.
h.Analysis of pre-launch test results and instrument characterization data sets.
3.3. Assess the Long-Term quality of the NPP Land EDRs for accomplishing NASA’s climate research needs.
The Land PEATE shall perform the following assessment of SDRs including:
Assessment of the long-term radiometric stability of the VIIRS Land bands
Assessments of the instrument corrections (e.g., temperature, RVS, polarization.)
Ongoing assessment of geolocation accuracy and adjustments to geolocation LUTs to improve earth-location accuracy will be performed by the geolocation team funded by the NPP Project Science Office. While not included in the Land PEATE effort, accurate geolocation is required by most land products and is vital to product quality assessment activities especially those that involve time series analyses over test sites.
3.3Provide suggested algorithm improvements to the IDPS via the PSWG.
The Land PEATE shall support the delivery of improved algorithms from the VLST to the IDPS via the PSWG. This activity includes the following:
a. Receiving an improved algorithm or software which implements it from a member of the VLST and integrating it into the MODAPS processing system. This step includes configuration management and unit and chain testing to verify that the algorithm works properly for a limited set of test cases.
b. Conducting larger scale science tests which incorporate the proposed improvement within existing production streams to produce 8 or more data days worth of products.
c. Packaging the improved software, its documentation and test results into deliveries to the NPP Project’s Integration and Test facility in a TBD agreed upon format and contents. The I&TF staff who are funded by the NPP Project will re-work the delivery into a format that can run in the IDPS and compare results of production runs in the I&TF with products generated in the PEATE. PEATE staff will be available to answer questions that the I&TF staff may have with regard to the software delivery.
3.4Process selected data subsets in support of Calibration/Validation and Algorithm improvement activities
The Land PEATE shall provide the capability to process any desired set of VIIRS data, up to and including the full mission data set, from RDRs to Land EDRs and the Level 3 gridded products used to evaluate quality of the EDRs.
3.5 Process RDRs to SDRS using standard 0 to Level 1 software provided by the IPO
The Land PEATE shall provide the capability to process RDRs to SDRs using the standard Level 0 to Level 1 software provided by the IPO. This will include the capability to accept alternative LUTs provided by the NVCST.
3.6 Process SDRs to Land EDRs using standard Land algorithms, software and LUTS provided by the IPO.
The Land PEATE shall provide the capability to process SDRs to Land EDRs using the standard Land algorithms, software and LUTS provided by the IPO.
3.7 Process SDRs to Land EDRs using the standard Land algorithms and software, and alternative LUTS generated locally by the VLST.
The Land PEATE shall provide the capability to process SDRs to Land EDRs using the standard Land algorithms and software, and alternative LUTS generated locally by the VLST.
3.8 Process SDRs to Land EDRs using alternative algorithms, software and LUTS provided by the VLST
The Land PEATE shall provide the capability to process SDRs to Land EDRs using alternative algorithms, software and LUTS provided by the VLST, to evaluate potential algorithm improvements and additional products.
3,9 Support Cataloging, search, browse, ordering, and distribution
The Land PEATE shall support cataloging, searching, ordering and distributing of all internally processed data products.
3.10 Additional Requirements
The Land PEATE shall support the following general requirements:
Shall be capable of unattended operations on at least one shift per day
Shall retrieve data from the SD3 server at an average rate of 1 day per day but have the capacity to retrieve data at rates of up to 5 data days per day such that no data products are lost from the 16-day rolling buffer on the SD3.
Shall have the processing resources to be able to complete a science test that involves generating 8 data-days of global products within 3 working days provided the science software runs without error.
Operations Concept
The Land PEATE operations concept is built on the MODIS Adaptive Processing System (MODAPS) originally developed to support MODIS processing and the integrated Land Team/ Science Data Support Team approach for software integration and testing and product quality assessment. The basic elements of this approach are:
An integrated team supporting all activities, including systems, software, data processing, product quality assessment, calibration, validation, and distribution;
Substantial processing capacity, to support rapid, multiple evaluations of potential algorithm improvements;
Close cooperation with the scientific community in algorithm and product evaluation and in product validation.
The following sections summarize the activities to be performed in support of VIIRS EDR assessment at the Land PEATE, followed by a summary of facilities to be provided.
4.1 VIIRS Land EDR Assessment
Assessment of a satellite-based sensor, such as VIIRS, should be both global in scope and should be a continuing process throughout the life of a satellite mission, particularly if the data products are to be used in a long-term, multi-sensor time series. For VIIRS, continuous validation is necessary for the assessment of the accuracy of the calibration across platforms.
4.1.1VIIRS Data Acquisition and Management
The complete set of VIIRS RDRs will be acquired as made available from the SD3. Selected SDRs and EDRs will also be acquired as needed for calibration and data product assessment. The fraction of data to be acquired is still TBD. The facilities for storing and managing the acquired data are described in Section 4.2.
4.1.2Pre-launch and Early Mission Testing and Verification
The Land PEATE will support several critical activities during the pre-launch phase of NPP. These include: verification of the science algorithm and operational processing code; evaluation of test versions of the EDRs, produced by the IDPS from simulated data and transmitted to the SD3; and quick-response processing of instrument test data sets, as soon as they are acquired from the SD3.
The processing code will be acquired and installed in the MODAPS to support verification and testing. The initial versions are expected to be the science algorithm code, which will be obtained by the NVLST and provided to the PEATE. As operational software becomes available in the I&TS, it will be acquired directly by the PEATE. The pre-launch versions of the software will be tested and verified using simulated data sets, either SDRs or RDRs. In order to fully exercise the logic of the land EDR algorithms, high-fidelity simulated data with realistic radiances over land and clouds and geographically correct land pixels will be required.
These same data sets, along with sample EDRs produced by IDPS, will also be used to test EDR evaluation procedures to be used during the mission. The types of evaluations to be performed are described in other sections, below.
Finally, these capabilities in the PEATE will be used to acquire and process the pre-launch instrument test data sets for analysis by the NVLST. The test data sets will be acquired from the SD3 as they become available, immediately processed as needed (i.e., RDR to SDR) and made available to the NVLST. This quick turnaround will be absolutely critical during instrument testing, to allow feedback from the NVLST to the VIIRS test team while the tests are still in progress. By analyzing test results during the actual testing, the NVLST will determine whether tests need to be re-run, either in original or modified form, to achieve the required instrument characterization result.
4.1.2 Evaluation Processing
To evaluate the efficacy of changes to the VIIRS SDR processing and the cross-calibration with MODIS/Aqua, we will develop the capability to process VIIRS RDRs in the MODAPS to produce land EDRs and Level 3 gridded products. We will use this capability to process limited amounts of VIIRS data for validation activities, and larger amounts of VIIRS data for global, long time-series analyses. This will enable evaluation of multiple versions of the VIIRS mission data, similar to that which was performed for MODIS science testing and the generation of MODIS experimental products.
4.1.3 Global Comparative Time Series Analyses
We will perform global comparative time-series analysis between VIIRS and MODIS standard, archived level-3 products, and repeat the entire analysis following any reprocessing campaign. For periods beyond the life of the MODIS mission, we will perform comparisons with data collected from land validation sites and other fine to moderate-resolution land sensors.
4.1.5 Scientific Community Involvement
The MODIS land team has held a series of successful workshops that focused on algorithms, quality assessment and validation results for suites of related land products (e.g. albedo, vegetation indices, land cover conversion, net primary productivity). We propose to follow this approach to engage the community in the evaluation and improvement of VIIRS land EDRs by holding workshops at NASA GSFC, which will be open to all interested members of the community. These will follow the same general format as previously used for the MODIS land workshops.
We will maintain a public Web site for all of our VIIRS activities. This will include results and proceedings of the workshops; descriptions of proposed algorithm changes and calibration methodologies; results of data analyses, processing tests and product evaluations; and sample products for outside evaluation.
4.2 Systems and Facilities
The systems and facilities of Code 922/923 and University of Maryland land science group provide an effective environment for performing the assessment of NPP VIIRS land products. By leveraging an existing infrastructure developed specifically for this type of work, NASA will receive the maximum benefit for a minimum of cost. This group has demonstrated expertise in producing global products for land imaging instruments (Landsat, AVHRR and MODIS) and performing algorithm updates, testing and quality assessment on the products. The computing systems and their staff are co-located with the LDOPE (Land Data Operational Production Evaluation) team, and VIIRS land science team members. The MODAPS is high-capacity (producing upwards of 3TB per day) production-proven system that has been providing high-quality science products to the land, atmosphere and ocean communities on a daily basis since February 2000.
4.2.1 Data Acquisition and Distribution
The MODAPS currently acquires MODIS data (Terra and Aqua) through an ftp server connected to the GES DAAC but has the capability to process data from the EDOS bent pipe when more rapid production is required. Standard products produced in MODAPS at the rate of 3TB per day are archived and distributed by three DAACs. The MODAPS system also distributes approximately over 500GB of products per day to the MODIS science team through subscriptions to facilitate their quality assessment, algorithm improvement and validation efforts. In addition results from science tests are maintained online for science team analysis and experimental, interim and selected Level 3 products are also available for ordering from web-based search/order/distribution system.
A similar approach will be followed to enable the VLST to rapidly access the results of VIIRS EDR product evaluation processing and large scale testing.
4.2.2 Development
Our group has the infrastructure, knowledge, and experience to support algorithm improvements for VIIRS land products and validation activities. The modular design of the MODAPS system allows developers to easily add new product generation software without changes to the production system itself. The similarity between MODIS and VIIRS instruments and the science algorithms is such that few changes are expected to be required in the production rules that govern all aspects of how products are generated.
4.2.3 Physical Facilities
The GSFC code 922 team has a well-supported facility located in Building 32 of Goddard's Greenbelt campus. The servers reside in a 4,000 square foot raised floor computer area. The critical infrastructure required to operate a large computer facility is already in place. The room is supported by 10 air handler units, and has 250KVA of uninterruptible power fed by dual building UPSes that are backed up by diesel generators. Environmental monitoring is active 24x7 as well with automated monitoring of fire and flood sensors as well as automated monitoring of computer systems to detect abnormal conditions in the system logs related to hardware errors. Hardware and software maintenance contracts are in place and kept up to date. Critical data and software are backed up to a server located in Building 33. The computing systems within the facility are compliant with the level of IT security required for special management attention systems and undergo security audits every 6 months. The systems are supported by staff located on site.
The Office of Earth Science (OES) of the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) Integrated Program Office (IPO), have agreed to jointly implement a mission called the NPOESS Preparatory Project (NPP). NPP has the objectives listed below.
1.Demonstrate and validate:
a.A global imaging radiometer and a suite of two sounding instruments, associated algorithms, and data processing
b.An ozone mapping and profiling instrument, associated algorithms, and data processing
c.A NPP Command, Control and Communications Segment (C3S), an Interface Data Processing Segment (IDPS), an Archive and Distribution Segment (ADS), and a Science Data Segment (SDS).
2.Provide continuity of systematic, global, calibrated, validated and geo-located Earth science imaging radiometry, sounding observations, and ozone mapping and profiling observations for NASA Earth Science research.
This document specifies the requirements and concept of operations for the NPP Land PEATE (Product Evaluation and Test Element) that will be managed and developed by NASA. As defined in NASA’s NPP Level 1 Requirements (see Appendix 1), the role of the SDS is principally directed to the assessment and verification of NPP product quality, where those products are identified as Raw Data Records, Sensor Data Records, and Environmental Data Records (RDRs, SDRs, and EDRs, respectively). In executing its responsibilities for assessment and verification, the following SDS functions will be performed:
Acquire RDRs, SDRs, and VIIRS Land EDRs from the SDS
Assess the quality of the VIIRS Land EDRs for accomplishing NASA’s climate research requirements
Provide suggested algorithm improvements to the IDPS via the Project Science Working Group (PSWG)
Process selected data subsets … in support of Calibration/Validation activities
Interfaces
The NPP Land PEATE will support interfaces with the following facilities and organizations:
2.1SDS Data Delivery Depository (SD3) Component
The Land PEATE will acquire all VIIRS RDRs, and selected SDRs and Land EDRs from the SD3. All RDRs will be acquired as they are made available at the SDS interface, while selected SDRs and EDRs will be acquired on request.
2.2NASA NPP Characterization Support Team (NCST)
The Land PEATE will interact with the NCST in support of VIIRS calibration including running large-scale tests of improved calibration software in the Land PEATE. The NCST will provide calibration Look-Up Tables (LUTs) for evaluation, which may utilize more recent calibration measurements than the operational LUTS provided by the IDPS. The Land PEATE will provide the results of calibration evaluations to the NCST.
2.3VIIRS Land Science Team (VLST)
The NPP Land PEATE will be co-located with members of the VLST and will be the primary facility for analyses and evaluations performed by the VLST. The VLST will provide proposed algorithm improvements and evaluation processing requests to the PEATE and serve as the primary liaison between the NASA Land research community and the NPP Land PEATE. The PEATE will provide standard SDRs and EDRs acquired from SD3, and SDRs, EDRs and Level 3 land products generated to support product evaluation and validation activities to the VLST.
2.4Ancillary Data Providers
The Land PEATE will acquire ancillary data products needed for EDR processing from various providers. The ancillary products required by VIIRS Land EDRs running in the IDPS will be documented in the Environmental Data Records Interdependency Report (D36385). The Land PEATE will also acquire additional ancillary data products identified by the VLST as required for testing improved algorithms for the generation of EDRs.
Requirements
The NPP Land PEATE will meet the following requirements.
3.1Acquire RDRs, SDRs, and Land EDRs from the SDS
The Land PEATE shall receive the all Visible and Infrared Imager/Radiometer suite (VIIRS) RDRs and SDRs and the following Land EDRs:
Albedo (Surface)
Land Surface Temperature
Vegetation Index
Snow Cover and Depth
Surface Type
Active Fires
Ice Surface Temperature
The Land PEATE shall ingest the all VIIRS RDRs as they are made available at the SD3 interface, nominally within 1 day but always within 16 days of availability.
The Land PEATE shall ingest selected subsets of the SDRs and EDRs as specified by the VLST, for assessment and validation.
The Land PEATE shall provide storage for VIIRS RDRs, SDRs and EDRs as follows:
One full-mission set of RDRs (i.e. one year of RDRs for each year of the mission).
120 data-days of SDRs
Two full-mission sets (i.e. two 1 year sets of EDRs, an improved and a baseline set, for each year of the mission) of Land EDRs.
An additional 25% margin in storage capacity will be provided as requested by the NPP System Engineer upon receipt of additional funding from the NPP Project.
3.2Assess the quality of the NPP Land EDRs for accomplishing NASA’s climate research needs.
The Land PEATE shall support the NVLST in performing the following assessments of the Land EDRs:
a.Ground truth validation using satellite observations acquired over land validation sites and in-situ data acquired by instrumentation at the sites.
b.Cross-comparisons with concurrent satellite data sets (e.g., MODIS)
c.Comparisons with the long-term data sets from past missions (e.g., AVHRR)
d.Assessments of product in terms of internal consistency and expected trends over time (time series analysis of seasonal variability and outlier identification).
e.Assessments of the effectiveness of masking algorithms (e.g., clouds, land/water boundaries)
f.Pre-launch assessment of algorithm functionality and implementation using simulated TOA radiances in the SDR format.
g.Assessments of the impact of algorithm changes on products downstream in the processing chain.
h.Analysis of pre-launch test results and instrument characterization data sets.
3.3. Assess the Long-Term quality of the NPP Land EDRs for accomplishing NASA’s climate research needs.
The Land PEATE shall perform the following assessment of SDRs including:
Assessment of the long-term radiometric stability of the VIIRS Land bands
Assessments of the instrument corrections (e.g., temperature, RVS, polarization.)
Ongoing assessment of geolocation accuracy and adjustments to geolocation LUTs to improve earth-location accuracy will be performed by the geolocation team funded by the NPP Project Science Office. While not included in the Land PEATE effort, accurate geolocation is required by most land products and is vital to product quality assessment activities especially those that involve time series analyses over test sites.
3.3Provide suggested algorithm improvements to the IDPS via the PSWG.
The Land PEATE shall support the delivery of improved algorithms from the VLST to the IDPS via the PSWG. This activity includes the following:
a. Receiving an improved algorithm or software which implements it from a member of the VLST and integrating it into the MODAPS processing system. This step includes configuration management and unit and chain testing to verify that the algorithm works properly for a limited set of test cases.
b. Conducting larger scale science tests which incorporate the proposed improvement within existing production streams to produce 8 or more data days worth of products.
c. Packaging the improved software, its documentation and test results into deliveries to the NPP Project’s Integration and Test facility in a TBD agreed upon format and contents. The I&TF staff who are funded by the NPP Project will re-work the delivery into a format that can run in the IDPS and compare results of production runs in the I&TF with products generated in the PEATE. PEATE staff will be available to answer questions that the I&TF staff may have with regard to the software delivery.
3.4Process selected data subsets in support of Calibration/Validation and Algorithm improvement activities
The Land PEATE shall provide the capability to process any desired set of VIIRS data, up to and including the full mission data set, from RDRs to Land EDRs and the Level 3 gridded products used to evaluate quality of the EDRs.
3.5 Process RDRs to SDRS using standard 0 to Level 1 software provided by the IPO
The Land PEATE shall provide the capability to process RDRs to SDRs using the standard Level 0 to Level 1 software provided by the IPO. This will include the capability to accept alternative LUTs provided by the NVCST.
3.6 Process SDRs to Land EDRs using standard Land algorithms, software and LUTS provided by the IPO.
The Land PEATE shall provide the capability to process SDRs to Land EDRs using the standard Land algorithms, software and LUTS provided by the IPO.
3.7 Process SDRs to Land EDRs using the standard Land algorithms and software, and alternative LUTS generated locally by the VLST.
The Land PEATE shall provide the capability to process SDRs to Land EDRs using the standard Land algorithms and software, and alternative LUTS generated locally by the VLST.
3.8 Process SDRs to Land EDRs using alternative algorithms, software and LUTS provided by the VLST
The Land PEATE shall provide the capability to process SDRs to Land EDRs using alternative algorithms, software and LUTS provided by the VLST, to evaluate potential algorithm improvements and additional products.
3,9 Support Cataloging, search, browse, ordering, and distribution
The Land PEATE shall support cataloging, searching, ordering and distributing of all internally processed data products.
3.10 Additional Requirements
The Land PEATE shall support the following general requirements:
Shall be capable of unattended operations on at least one shift per day
Shall retrieve data from the SD3 server at an average rate of 1 day per day but have the capacity to retrieve data at rates of up to 5 data days per day such that no data products are lost from the 16-day rolling buffer on the SD3.
Shall have the processing resources to be able to complete a science test that involves generating 8 data-days of global products within 3 working days provided the science software runs without error.
Operations Concept
The Land PEATE operations concept is built on the MODIS Adaptive Processing System (MODAPS) originally developed to support MODIS processing and the integrated Land Team/ Science Data Support Team approach for software integration and testing and product quality assessment. The basic elements of this approach are:
An integrated team supporting all activities, including systems, software, data processing, product quality assessment, calibration, validation, and distribution;
Substantial processing capacity, to support rapid, multiple evaluations of potential algorithm improvements;
Close cooperation with the scientific community in algorithm and product evaluation and in product validation.
The following sections summarize the activities to be performed in support of VIIRS EDR assessment at the Land PEATE, followed by a summary of facilities to be provided.
4.1 VIIRS Land EDR Assessment
Assessment of a satellite-based sensor, such as VIIRS, should be both global in scope and should be a continuing process throughout the life of a satellite mission, particularly if the data products are to be used in a long-term, multi-sensor time series. For VIIRS, continuous validation is necessary for the assessment of the accuracy of the calibration across platforms.
4.1.1VIIRS Data Acquisition and Management
The complete set of VIIRS RDRs will be acquired as made available from the SD3. Selected SDRs and EDRs will also be acquired as needed for calibration and data product assessment. The fraction of data to be acquired is still TBD. The facilities for storing and managing the acquired data are described in Section 4.2.
4.1.2Pre-launch and Early Mission Testing and Verification
The Land PEATE will support several critical activities during the pre-launch phase of NPP. These include: verification of the science algorithm and operational processing code; evaluation of test versions of the EDRs, produced by the IDPS from simulated data and transmitted to the SD3; and quick-response processing of instrument test data sets, as soon as they are acquired from the SD3.
The processing code will be acquired and installed in the MODAPS to support verification and testing. The initial versions are expected to be the science algorithm code, which will be obtained by the NVLST and provided to the PEATE. As operational software becomes available in the I&TS, it will be acquired directly by the PEATE. The pre-launch versions of the software will be tested and verified using simulated data sets, either SDRs or RDRs. In order to fully exercise the logic of the land EDR algorithms, high-fidelity simulated data with realistic radiances over land and clouds and geographically correct land pixels will be required.
These same data sets, along with sample EDRs produced by IDPS, will also be used to test EDR evaluation procedures to be used during the mission. The types of evaluations to be performed are described in other sections, below.
Finally, these capabilities in the PEATE will be used to acquire and process the pre-launch instrument test data sets for analysis by the NVLST. The test data sets will be acquired from the SD3 as they become available, immediately processed as needed (i.e., RDR to SDR) and made available to the NVLST. This quick turnaround will be absolutely critical during instrument testing, to allow feedback from the NVLST to the VIIRS test team while the tests are still in progress. By analyzing test results during the actual testing, the NVLST will determine whether tests need to be re-run, either in original or modified form, to achieve the required instrument characterization result.
4.1.2 Evaluation Processing
To evaluate the efficacy of changes to the VIIRS SDR processing and the cross-calibration with MODIS/Aqua, we will develop the capability to process VIIRS RDRs in the MODAPS to produce land EDRs and Level 3 gridded products. We will use this capability to process limited amounts of VIIRS data for validation activities, and larger amounts of VIIRS data for global, long time-series analyses. This will enable evaluation of multiple versions of the VIIRS mission data, similar to that which was performed for MODIS science testing and the generation of MODIS experimental products.
4.1.3 Global Comparative Time Series Analyses
We will perform global comparative time-series analysis between VIIRS and MODIS standard, archived level-3 products, and repeat the entire analysis following any reprocessing campaign. For periods beyond the life of the MODIS mission, we will perform comparisons with data collected from land validation sites and other fine to moderate-resolution land sensors.
4.1.5 Scientific Community Involvement
The MODIS land team has held a series of successful workshops that focused on algorithms, quality assessment and validation results for suites of related land products (e.g. albedo, vegetation indices, land cover conversion, net primary productivity). We propose to follow this approach to engage the community in the evaluation and improvement of VIIRS land EDRs by holding workshops at NASA GSFC, which will be open to all interested members of the community. These will follow the same general format as previously used for the MODIS land workshops.
We will maintain a public Web site for all of our VIIRS activities. This will include results and proceedings of the workshops; descriptions of proposed algorithm changes and calibration methodologies; results of data analyses, processing tests and product evaluations; and sample products for outside evaluation.
4.2 Systems and Facilities
The systems and facilities of Code 922/923 and University of Maryland land science group provide an effective environment for performing the assessment of NPP VIIRS land products. By leveraging an existing infrastructure developed specifically for this type of work, NASA will receive the maximum benefit for a minimum of cost. This group has demonstrated expertise in producing global products for land imaging instruments (Landsat, AVHRR and MODIS) and performing algorithm updates, testing and quality assessment on the products. The computing systems and their staff are co-located with the LDOPE (Land Data Operational Production Evaluation) team, and VIIRS land science team members. The MODAPS is high-capacity (producing upwards of 3TB per day) production-proven system that has been providing high-quality science products to the land, atmosphere and ocean communities on a daily basis since February 2000.
4.2.1 Data Acquisition and Distribution
The MODAPS currently acquires MODIS data (Terra and Aqua) through an ftp server connected to the GES DAAC but has the capability to process data from the EDOS bent pipe when more rapid production is required. Standard products produced in MODAPS at the rate of 3TB per day are archived and distributed by three DAACs. The MODAPS system also distributes approximately over 500GB of products per day to the MODIS science team through subscriptions to facilitate their quality assessment, algorithm improvement and validation efforts. In addition results from science tests are maintained online for science team analysis and experimental, interim and selected Level 3 products are also available for ordering from web-based search/order/distribution system.
A similar approach will be followed to enable the VLST to rapidly access the results of VIIRS EDR product evaluation processing and large scale testing.
4.2.2 Development
Our group has the infrastructure, knowledge, and experience to support algorithm improvements for VIIRS land products and validation activities. The modular design of the MODAPS system allows developers to easily add new product generation software without changes to the production system itself. The similarity between MODIS and VIIRS instruments and the science algorithms is such that few changes are expected to be required in the production rules that govern all aspects of how products are generated.
4.2.3 Physical Facilities
The GSFC code 922 team has a well-supported facility located in Building 32 of Goddard's Greenbelt campus. The servers reside in a 4,000 square foot raised floor computer area. The critical infrastructure required to operate a large computer facility is already in place. The room is supported by 10 air handler units, and has 250KVA of uninterruptible power fed by dual building UPSes that are backed up by diesel generators. Environmental monitoring is active 24x7 as well with automated monitoring of fire and flood sensors as well as automated monitoring of computer systems to detect abnormal conditions in the system logs related to hardware errors. Hardware and software maintenance contracts are in place and kept up to date. Critical data and software are backed up to a server located in Building 33. The computing systems within the facility are compliant with the level of IT security required for special management attention systems and undergo security audits every 6 months. The systems are supported by staff located on site.
Wednesday 18 July 2007
The Eifel A Short History
Even though the history of the Eifel can be traced back much farther, one of the most historical events that influenced the whole region was the Gallic War, (58-50 BC) when the Romans under Julius Caesar defeated the Kelts and began to settle in the valley along the Mosel River.
This area was very important for trade purposes, because several water ways- the Saar, Mosel, Ruver, and Rhine Rivers met not far away, and the Romans could control much of the shipping to many different locations.
During the approximately 400 years of Roman Rule, many beautiful structures including Villas, Cathedrals, and Monasterys were built through-out the Eifel, several of which are still standing.
Perhaps one of the greatest Engineering feats during this time was the Viaduct constructed to bring fresh drinking water from the Eifel Mountains to Cologne. Parts of this can still be seen.
This area was very important for trade purposes, because several water ways- the Saar, Mosel, Ruver, and Rhine Rivers met not far away, and the Romans could control much of the shipping to many different locations.
During the approximately 400 years of Roman Rule, many beautiful structures including Villas, Cathedrals, and Monasterys were built through-out the Eifel, several of which are still standing.
Perhaps one of the greatest Engineering feats during this time was the Viaduct constructed to bring fresh drinking water from the Eifel Mountains to Cologne. Parts of this can still be seen.
resetter printer for ip 1200-1600
CANON
Pixma of iP1200 and iP1600
Procedure to Reset Ink Tank Full Error for Canon IP1200 and IP1600
First Step (Hardware Reset)
1. Turn Off the printer, and then take off the cable power.
2. Push and hold the power button (use your fore finger to hold the power button).
3. Connect again the power cable.
4. Use your middle finger to push the resume button 2 times.
5. Release the power button.
6. Finish. you have finised the first step to reset Ink Tank Full Error (Blink Error).
Second Step (Software Reset by GeneralTool) for Permanent
1. Download IP1200, 1600, 2200 Resetter from here http://www.printersiam.com/data/download/ip1600st.zip
2. Unzip in folder C:\IP1200 (if you use Windows 98 you need use winzip http://www.winzip.com)
3. Make sure all files attribute have not Read Only.
4. Run GeneralTool.exe
5. At USB Port choose your printer port.
6. Click Lock Release
7. Check EEPROM CLEAR
8. Put in blank paper for printing. And then click Test Pattern 1 button
9. It's All Done. Your Printer IP1200, IP1600, and iP2200 back normal again.
Pixma of iP1200 and iP1600
Procedure to Reset Ink Tank Full Error for Canon IP1200 and IP1600
First Step (Hardware Reset)
1. Turn Off the printer, and then take off the cable power.
2. Push and hold the power button (use your fore finger to hold the power button).
3. Connect again the power cable.
4. Use your middle finger to push the resume button 2 times.
5. Release the power button.
6. Finish. you have finised the first step to reset Ink Tank Full Error (Blink Error).
Second Step (Software Reset by GeneralTool) for Permanent
1. Download IP1200, 1600, 2200 Resetter from here http://www.printersiam.com/data/download/ip1600st.zip
2. Unzip in folder C:\IP1200 (if you use Windows 98 you need use winzip http://www.winzip.com)
3. Make sure all files attribute have not Read Only.
4. Run GeneralTool.exe
5. At USB Port choose your printer port.
6. Click Lock Release
7. Check EEPROM CLEAR
8. Put in blank paper for printing. And then click Test Pattern 1 button
9. It's All Done. Your Printer IP1200, IP1600, and iP2200 back normal again.
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