EOS AM-1 (now renamed "Terra") is scheduled for launch July 28, 1999. This article summarizes the readiness of Terra for launch and the expectations for the data products in the first several months of the mission. With this article we want to start a close, well-informed collaboration with the Interdisciplinary Science (IDS) community. This article is based on presentations in the last Science Working group for the AM Platform (SWAMP) Meeting in Boulder, CO, held in February 1999, and is motivated by the EOS Science Executive Committee’s call for providing more information to the community and a tighter link. Several events preceded this article and the very up-beat spirit of the last SWAMP meeting that we would like to convey to you.
Among the highlights at the SWAMP meeting were the reports by Chris Scolese (EOS Program Manager), Kevin Grady (Terra Project Manager), and Jack Leibee (Terra Mission Manager) concerning the readiness of the instruments, the spacecraft, the launch vehicle, and, yes, the flight operation software for launch. The launch is scheduled for July 28, 1999 from Vandenberg Air Force Base on the west coast, but is still subject to coordination with other, non-NASA missions. In the last few months there was a major breakthrough in the development of the flight operations software, our obstacle for launch in the last year. A highly experienced Raytheon team, under new (and highly experienced) NASA management, made a fast recovery and generated the EMOS software that will be used for the operation of Terra, as well as the subsequent EOS PM-1 mission (see Perkins),The Earth Observer, 1998, Vol. 10, No. 6).
An end-to-end test conducted in late January demonstrated the excellent capability of the system to the satisfaction of the Terra Flight Operations Team, headed by Bob Kozon, the Terra manager, and us, the Project Science Team. Jack Leibee is the new mission manager, with responsibility for integrating flight and ground segments and assuring overall readiness for flight. He has many years of experience in development and integration of flight software and flight operations in NASA. After the January test, Leibee anticipates no roadblocks that would prohibit a July launch. He emphasized that the success of EMOS was made possible, at least in part, by the excellent teamwork between the government and several industry groups involved in the project. Kevin Grady reported that the flight segment is in excellent shape. There are no major issues that need to be resolved. The launch delay was used to modify the MODIS electronics to reduce an electronics crosstalk issue, and to evaluate the impact of partial failure of one of the power supplies on the CERES instrument on TRMM. To be safe, new power supplies were ordered and will be installed on CERES. The ATLAS II AS launch vehicle was manufactured 2 years ago and is set for launch.
EOS AM-1 was renamed through an international contest (conducted jointly by NASA and the American Geophysical Union) open to students in grades 8-12 (see press release on page 26). Further information on the Terra mission, the contest, and the winning contest essay and those of the other Top 10 finalists, may be found on the Terra Web site at: http://terra.nasa.gov
The Terra Project Science Office is spearheading creation of the Earth Observatory (EOb). David Herring is responsible for this activity. (The prototype URL is http: //modarch.gsfc.nasa.gov/EO/eo_home. html; login and password are both "eob".) We hope this Web environment will become the NASA Web portal where the general public goes to learn about the Earth. As such, it will showcase new images and science results from EOS missions. The focus in its first year of operation (beginning April 15, 1999) will be on SeaWiFS, TRMM, Landsat 7, SeaWinds, and Terra. All resources produced for the EOb will be freely available for use by the scientific community, museums, educators, public media, regional "stakeholders," environmental awareness groups, and interested members of the general public.
To provide overarching guidance and review for Terra outreach activities, as well as to flag "mature" new science results ready for public release, an Executive Committee for Science Outreach (ECSO) was formed. This committee is chaired by Prof. V. Ramanathan, of the Center for Clouds, Chemistry, and Climate, Scripps Institution of Oceanography. The purpose of this committee is to "harvest" new Terra science results that are ready for public release, as well as to help temper the presentation of new results with respect to socio-political implications they may have.
To meet the public media’s (primarily TV, newspapers, and our EOb Web site) requirements for quick access to satellite imagery of significant, newsworthy Earth events (e.g., severe storms, floods, El Niño, volcanic eruptions, wildfires), the Terra Project Science Office is forming a Rapid Response Network, to be headed by Jim Collatz, Associate Terra Project Scientist. After launch, this network will enable us to access and produce remote-sensing imagery of targets of interest within a matter of hours to days after acquisition.
Following is the calendar of main events in preparation for the launch:
Jan. 15
Jan. 28
March 15
March 29
April 6
April 15
April 22
April 21/22
May 4
June 1
July 28
The following provides information on Terra Data Products and expected timing for release of these products. These dates are relative to the actual launch date. The actual dates of release of specific data products depend on the complexity of the product and successful calibration and validation. We anticipate two main stages in the release of each product: a Beta release based on preliminary calibration and quick validation, and a science data release once a first estimate of the accuracy of the products is established. We want to engage the science community in finding problems and validating the Beta release, to enable a timely release of the science data products. The Tables on pages 14-18 list the EOS measurements that will be derived from the Terra mission, together with names of specific data products, algorithm developers, and expected dates of product availability. For more details see the EOS Data Products Handbook at: http://eospso.gsfc.nasa. gov/eos_ homepage/misc_html/data_prod.html. The algorithms are documented on the EOS web site: http://eospso.gsfc.nasa. gov/atbd/pg1.html. For each algorithm the expected time frame after launch for delivery of the Beta data products is identified. The science quality data will be available as soon as validation of the product is conducted. The Beta data are basically the product of "at launch" algorithms with only gross errors removed: not yet validated to science quality. These are useful for the community to start getting a feel for formats and data and perhaps start thoughts on hypotheses, but not ready to test hypotheses with any quantitative rigor. Study of these data also may reveal problems that are missed in the initial team validation efforts. The assessment of the quality of the data needed for the scientific research will take anywhere between three months and two years to complete. A statement of the expected data quality will accompany the data when they are delivered to the DAACs, in both their Beta form and in science form. The production level of Level 1 (radiometrically calibrated data with geolocation) is 100%. The production of Level 2 — 4 was set to 50% directly after launch increasing to 100% a year or two after launch. The teams have specific plans to select the data to be analyzed to the higher level:
MODIS Level 1- produce 100%. Atmospheric products- produce Level 2 every second day and all Level 3 using the time sub-sampled Level 2s. Land products- produce full-resolution Level 2-3 data for approximately half of the land masses, concentrating on regional subsets (including the U.S.), core validation sites and where NASA has intensive field experiments underway. Oceanic products- produce Level 2-3 globally by subsampling every second pixel.
MISR Level 1 radiometrically calibrated data: selected portions at launch, rising to 100% at launch + 3 months. Level 1 geometrically map-projected data: up to 100% beginning at launch + 4 months assuming the Langley DAAC is fully functional for MISR operations. Level 2 top-of-atmosphere albedo, cloud, aerosol, and surface data: global coverage but with reduced temporal sampling beginning at launch + 4 months (approximately 25% data throughput), rising to 100% after approximately 2 years.
MOPITT will process 25%-50% of the data into Level 2. It will be made up of 25% clear-sky cases, and 25% broken cloud over the oceans. Plans for Level 3 production are in process.
CERES ERBE-like data products are processed 100%. Cloud products are analyzed initially over the 3 DOE-ARM sites and Chesapeake Light, to compare directly to Terra and TRMM analysis. CERES Level 2 surface and atmosphere radiative flux product uses every third month for Beta processing tests.
ASTER Level 1 processing is done in Japan and is not subject to the U.S. production limitations (100% will be produced). The Level 2 processing is primarily on demand, and production will be done based on user requests and hardware availability.
Day 0-20
Day 21-39
Day 30-45
Day 40-70
Day 71-90
Day 90-120
Day 120-150
Day 150-180
Day 180-210
Day 180-1000
Newer products and CERES products that require the generation of the new angular models from CERES on Terra will take 3 years after the Beta version, which will use ERBE-type angular models. The Terra Science Team wants to engage the science community in evaluating Terra measurements and the data products, in producing exciting science and applications using the data, and communicating new Terra images and science results to the general public. The EOSDIS archive system at the DAACs is sized to permit daily distribution of data approximately equal to the amount of data archived each day, including all Level 0 through Level 4 products. The users submit requests for data via the EOS Data Gateway (an enhanced version of the Version 0 EOSDIS interface). The requests are routed to the appropriate DAACs from which the data will be made available to the users via ftp or media shipment. The limit on sizing does not include the data distributed on a "subscription basis," i.e., standing orders for data that can be satisfied upon production before the data are archived. Subscription-based distribution is limited only by the available media and network bandwidth at each DAAC. Therefore EOS investigators that have routine use for Terra data can submit subscription requests, and the data will be automatically sent to them. The subscription function will be available when the DAACs are ready to become operational for Terra, in June for EDC, GDAAC, and LDAAC, and around launch for NSIDC. Subscription submittal is an operator-assisted function. This means that users need to contact User Services at a DAAC to have a subscription submitted on their behalf.
The Terra Science Data Validation program will go into full swing shortly after launch. A wide range of activities are planned. Some are highlighted here. As yet, schedule details are not firm, given the very recent commitment to a July launch. The full scope of activities is described in plans and summaries available on the EOS Validation Page: http://eospso.gsfc.nasa. gov/validation/valpage.html where the validation contact person for each team or subteam is given, as are links to team pages. Besides the teams, the program includes more than 30 investigations focused on validation of Terra data products. Typically partnered with a specific team, these investigations are briefly summarized on the Validation Page. Correlative measurements include regular data collections from individual surface sites and networks of surface stations, and episodic intensive field experiments, some with airborne measurement components including airborne simulator versions of the Terra satellite instruments. Simulators include the MODIS Airborne Simulator (MAS), AirMISR, MASTER (MODIS-ASTER), and MOPITT-A. All are integrated on the NASA ER-2, though low-altitude platforms are typical for MASTER. MATR is an additional sensor used for MOPITT algorithm development and validation (10, 4)*. Calibration and calibration validating activities will be an early focus, in addition to extensive artifact analysis and comparison of related satellite data products. Many vicarious calibration activities will occur intensively in October 1999. For example, ASTER and MODIS will use surface measurements at Railroad Valley (dry lakebed), sites in Australia, and surface temperature measurements from buoy arrays in Lake Tahoe and the Salton Sea for correlative measurements. Airborne measurements are also planned. In addition to Railroad Valley, MISR will make measurements at JPL in coordination with Terra and AirMISR overflights. Building on SeaWiFS heritage (9, 5)*, data from the Marine Optical Buoy (MOBY) anchored off Lanai and the monthly service cruises will be used by the MODIS-Ocean team. An initialization cruise into high-chlorophyll waters off southern California is planned for October. Other cruises will occur during the year including an Atlantic Meridional Transect cruise (Germany to Cape Town) in December that will also collect M-AERI (10, 3)* observations for SST validation. Following on the heritage of SCAR-C, a focused field experiment on fires and their aerosol and gaseous effluents is presently being planned for the northwest U.S. in Fall 1999 and includes MAS and MOPITT-A overflights as well as surface and in situ data. Following on pre-MOVE (11, 1)*, MOPITT plans a validation exercise at the Department of Energy (DoE) ARM site in Oklahoma in Spring 2000. SAFARI-2000 is an international field experiment focused on land cover, biosphere, fires, aerosols, and gaseous effluent, that will be conducted in southern Africa in August-September 2000. SAFARI-2000 has a strong Terra validation focus (10, 6)*. Extensive surface and in situ atmospheric observations, and remote-sensing observations from MAS, AirMISR, MOPITT-A, and other sensors are planned. Observations will also be obtained for marine stratus cloud systems off the Namibian coast. Observations from surface networks will play an integral part of the Terra validation effort. Data from AERONET (Holben et al)., Remote Sens. Environ., 66, 1-16, 1998) are key to validation of aerosol data products and atmospheric correction for many surface data products as well as characterization of surface bidirectional reflectance. These data will be heavily utilized. Networks of surface radiation sites will be used by CERES to validate surface radiation retrievals, especially in relationship to cloud conditions for sites specially instrumented with micropulse lidar. Detailed high-quality measurements of atmospheric structure and radiation from the DoE ARM site in Oklahoma, as well as ARM sites on the north slope of Alaska and in the tropical western Pacific will be used for validation of cloud data products produced by the teams. CERES has also developed surface radiation sites for mixed forest in Virginia and an ocean site off the mouth of the Chesapeake Bay. MOPITT will use analyses of FTIR and spectrometer measurements routinely collected at 18 Network for the Detection of Stratospheric Change (NDSC) stations and weekly airborne profile measurements (flask samples) at 5 sites obtained by NOAA Climate Monitoring and Diagnostics Laboratory (CMDL).
MODIS has developed a network of 24 core sites for validation of its land surface/ biosphere data products (10, 3 and 10, 6)*. This network is well integrated with AERONET and with various national and international programs, such as the LTER, GLCTS, FLUXNET, and BigFoot (http://modarch.gsfc.nasa.gov/MODIS/LAND/VAL/), taking advantage of ongoing and planned field work, including major field experiments. There is a well-coordinated Terra data collection plan, i.e., ASTER scenes for the core sites, and collection of MODIS Quick Airborne Looks (MQUALS) data by light aircraft at selected sites (see page 22).
In summary, the first year of Terra will involve a very intensive effort at early validation of the science data products over a wide range of disciplines.
Editor's Note: * The numbers in parentheses refer to volume and issue
of The Earth Observer.
Data Products
Terra Mission Calendar of Events After Launch
The EOSDIS Archive System and Subscription
Terra Validation Program – Year 1
Measurement EOS Terra Instrument Algorithm /Document Authors Expected §-data delivery (days after launch) INSTRUMENTAL Calibration /description of mission ASTER AST-01: Level 1B Data Processing H. Tsu, H. Fujisada, K. Arai, K. Fukue,
I. Sato, H. Watanabe, M. Kaku, A. Iwasaki, F. Sakuma 120 AST-06: Decorrelation Stretch R. Alley 120 AST-08: Digital Elevation Models H. Lang, R. Welch 120 CERES CER-SYS-1.0: Subsystem 1.0: Instrument Geolocate and Calibrate Earth Radiances R. Lee III, B. Childers, B. Barkstrom, G. Smith, D. Crommelynck, W. Bolden, J. Paden, D. Pandey, S. Thomas, R. Wilson, K. Bush, P. Hess, W. Weaver 120 MISR MISR-01: Level 1 Radiance Scaling and Conditioning C. Bruegge, D. Diner, R. Korechoff, M. Lee 90-120 MISR-02: Level 1 In-Flight Radiometric Calibration and Characterization C. Bruegge, N. Chrien, D. Diner, V. Duval, R. Korechoff, R. Woodhouse 90-120 MISR-03:Level 1 Georectification and Registration V. Jovanovic, S. Lewicki, M. Smyth, J. Zong, R. Korechoff 120-150 MISR-04:Level 1 In-Flight Geometric Calibration V. Jovanovic 120-150 MISR-05:Level 1 Ancillary Geographic Product S. Lewicki 90-120 MODIS MOD-28: MODIS: Level 1A Earth Location M. Nishihama, R. Wolfe, D. Solomon, F. Patt, J. Blanchette, A. Fleig, E. Masuoka 90-120 MODIS level 1b- Geolocated and Calibrated Radiances B. Guenther et al. 90-120 MOPITT MOP-01: MOPITT Calibrated and Geolocated Radiances University of Toronto and NCAR MOPITT Team 90-120 ATMOSPHERE Cloud Properties MODIS MOD-06: Discriminating Clear Sky from Cloud with MODIS S. Ackerman, K. Strabala, P. Menzel, R. Frey, C. Moeller, L. Gumley, B. Baum, C. Schaaf, G. Riggs, R. Welch 120-150 MODIS-04: Cloud Top Properties and Cloud Phase P. Menzel, K. Strabala 120-180 MOD-05: Cloud Retrieval Algorithms for MODIS: Optical Thickness, Effective Particle Radius, and Thermodynamic Phase M. King, S-C. Tsay, S. Platnick, M. Wang, K-N. Liou 120-180 MISR MISR-06: Cloud Detection Level 1 D. Diner, L. Di Girolamo, E. Clothiaux 120-150 MISR-07: Level 2 Cloud Detection and Classification D. Diner, R. Davies, L. Di Girolamo, A. Horvath, C. Moroney, J.-P. Muller,S. Paradise, D. Wenkert, J. Zong 150-180 CERES CER-SYS-4.1: Imager Clear-Sky Determination and Cloud Detection B. Baum, R. Welch, P. Minnis, L. Stowe, V. Tovinkere, P. Heck, S. Gibson, Q. Trepte, D. Doelling, S. Mayor, S.Sun-Mack, T. Murray, T. Berendes,. Christopher, K.S. Kuo, A. Logar,P. Davis 120-150
CER-SYS-4.2: Imager Cloud Layer and Height Determination B. Baum, P. Minnis, J. Coakley, B. Wielicki, P. Heck, V. Tovinkere, Q. Trepte, S. Mayor, T. Murray, S. Sun-Mack 150-180 CER-SYS-4.3: Cloud Optical P. Minnis, D. Young 150-180
Radiative Energy Fluxes CERES CER-SYS-2.0: ERBE-Like Inversion to InstantaneousTOA Fluxes R. N. Green, J. Robbins, L. Chang 120-150 CER-SYS-3.0: ERBE-Like Averaging to Monthly TOA Fluxes D. Young, T. Wong, P. Minnis, M. Mitchum, D. Doelling, G. Gibson L. Chang 150-180 CER-SYS-4.5: Inversion to Instantaneous TOA Fluxes R. N. Green, B. Wielicki, J. Coakley III, L. Stowe, P. Hinton 180-210 Radiative Energy Fluxes CERES CER-SYS-4.6: Empirical Estimates of Shortwave and Longwave Surface Radiation Budget Involving CERES Measurements B. Barkstrom, D. Kratz, R. A. Inamdar, V. Ramanathan, S. Gupta Cess, Z. Li, 180-210 CER-SYS-5.0: Compute Surface and Atmospheric Fluxes T. Charlock, F. Rose, D. Rutan, T. Alberta, L. Coleman, G. Smith, N. Manolo-Smith, T. Bess 80-210 CER-SYS-6.0: Grid Single Satellite Fluxes and Clouds and Compute Spatial Averages G. L. Smith, T. Wong, N. McKoy, K. Bush, R. Hazra, N. Manalo-Smith, D. Rutan, M. Mitchum 180-210 CER-SYS-10.0:Monthly Regional TOA and Surface Radiation Budget T. Wong, D. Young, P. Minnis, R. Cess, V. Ramanathan, M. Mitchum, D. Doelling, G. Gibson, S. Sullivan 180-210 CER-SYS-12.0:Regrid Humidity and Temperature Fields S. Gupta, A. Wilber, N. Richey, F. Rose, T. Alberta, T. Charlock, L. Coleman 180-210 MISR MISR-08:Level 2Top-of-Atmosphere Albedo D. Diner, R. Davies, T. Varnai, C. Moroney, C. Borel, S. Gerstl 150-210 Tropospheric Chemistry MOPITT MOP-02: Retrieved Carbon Monoxide Profiles and Column the NCAR MOPITT Team Amounts of Carbon Monoxide and Methane J. Gille, J. Wang, M. Deeter, D. Edwards, J. Warner, D. Ziskin and NCAR MOPITT Team 150-210 Aerosol Properties MISR MISR-09: Level 2 Aerosol Retrieval D. Diner, W. Abdou, T. Ackerman, K. Crean, H. Gordon, R. Kahn, J. Martonchik, S. McMuldroch, S. Paradise, B. Pinty, M. Verstraete, M. Wang, R. West 150-210 MISR-11: Level 2 Ancillary Products and Datasets D. Diner, W. Abdou, H. Gordon, R. Kahn, Y. Knyazikhin, J. Martonchik, S. McMuldroch, R. Myneni, R. West 150-210 MODIS MOD-02: Remote Sensing of Tropospheric Aerosol from MODIS: Optical thickness over land and ocean and aerosol size distribution over the ocean Y. Kaufman, D. TanrŽ, L. Remer, A. Chu, S. Mattoo, C. Ichoku 150-210 Atmospheric Temperature MODIS MOD-07: MODIS: Atmospheric Profile Retrieval P. Menzel, L. Gumley 20-150 Atmospheric Humidity MODIS MOD-03: MODIS: Near-IR Water Vapor Algorithm B-C. Gao, Y. Kaufman 150-180 LAND Land Cover & Land Use Change MODIS MOD-08: Atmospheric Correction Algorithm Spectral Reflectances E. Vermote 150-210 Vegetation dynamics MOD-09: BRDF/Albedo A. Strahler, X. Li, S. Liang, J.-P. Muller, M. Barnsley, P. Lewis MOD-12: Land Cover A. Strahler, J. Townshend, J. Borak, A. Hyman, E. Lambin, A. Moody, D. Muchoney 150-210 MOD-13: Vegetation A. Huete, C. Justice, W. van Leeuwen 150-210 MOD-15: LAI (leaf area index) and FPAR(fraction photosynthetically active radiation) S. Running, R. Myneni, R. Nemani, J. Glassy 210-360 MOD-16: PSN (daily photosynthesis) and ANPP (annual net primary production) S. Running, R. Nemani, J. Glassy 210-360 MISR MISR-10: Level 2 Surface Retrieval D. Diner, J. Martonchik, C. Borel, S. Gerstl, H. Gordon, Y. Knyazikhin, R. Myneni, B. Pinty, M. Verstraete 50-210 ASTER AST-04: Level 2B1- Surface Radiance and Level 2B5 - Surface Reflectance K. Thome, S. Biggar, P. Slater 150-210 Surface Temperature MODIS MOD-11: Land Surface Temperature Z. Wan, W. Snyder 150-210 ASTER AST-02: Brightness Temperature R. Alley 150-210 AST-03: Temperature/Emissivity Separation A. R. Gillespie, S. Rokugawa, S. J. Hook, T. Matsunage, A. Kahle 180-210 >AST-05: Atmospheric Correction Method for ASTER Thermal Radiometry Over Land F. Palluconi, G. Hoover, R. Alley, M. Jentoft-Nilsen, T. Thompson 150-210 Fire Products MODIS MOD-14: MODIS: Fire Products Y. Kaufman, C. Justice 150-210 OCEAN Surface Temperature MODIS MOD-25: Infrared Sea Surface Temperature Algorithm MODIS: O. Brown 150-210 Phytoplankton & Dissolved Organic Matter MOD-17: Normalized Water Leaving Radiance H. Gordon 150-210 MOD-18: Bio-Optical Algorithms: Case 1 Waters D. Clark 150-210 MOD-19: Case 2 Chlorophyll_a Algorithm and Case 2 Absorption Coefficient Algorithm K. Carder, S. Hawes, Z. Lee 150-210 MOD-20: Algorithm for Surface PAR and IPAR K. Carder, S. Hawes, R.F. Chen 80-210 MOD-21: Algorithm for Clear Water Epsilons K. Carder, C. Cattrall, R.F. Chen 150-210 MOD-22: Chlorophyll Fluorescence M. Abbott 150-210 MOD-23: Detached Coccolith Concentration H. Gordon, W. Balch 150-210 MOD-24: Annual Ocean Primary Productivity Algorithm W. Esaias 150-210 MOD-27: Phycoerythrin Pigment Concentration F. Hoge 150-210 CRYOSPHERE Sea Ice and Snow MODIS MOD-10: MODIS: Snow Mapping Algorithm and the Sea Ice Mapping Algorithm D. Hall, A. Tait, G. Riggs, V. Salomonson 150-210
ASTER AST-13 Polar Surface and Cloud Classification R. Welch 730