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  • Update with testing, procurements, design, fully staffed.
  • New Mexico is another state obligated to deliver water to Texas under the Rio Grande and Pecos River Compacts. Other available remote sensing tools do not now provide the level of detail needed to be useful.
  • Telescope qual level vibed prior to test, FPA shells cyro cycled, FPA qualvibed and cryo cycled

    1. 1. The Thermal Infrared Sensor on the Landsat Data Continuity Mission <br />IGARSS, Honolulu, HI<br />July 27, 2010<br />Dennis Reuter<br />TIRS Instrument Scientist<br />dennis.c.reuter@nasa.gov<br />301-286-2042<br />
    2. 2. Landsat Mission History<br />Landsat was first program proposed to monitor land surface data from space<br />Stimulated by recognition of successful atmospheric programs<br />Landsat 1 launched July 23, 1972<br />Originally called Earth Resources Technology Satellite (ERTS)<br />Visible/Near IR multispectral mapper.<br />Landsat 3, launched March 5, 1978, included one thermal band (10-12 mm)<br />Following missions also included thermal band<br />2<br />
    3. 3. 3<br />Landsat Data Continuity Mission (LDCM)<br />LDCM is the follow-on to Landsat 7 with launch in Dec., 2012<br />LDCM provides data continuity with previous Landsats<br />Operational Land Imager (OLI)<br />Thermal Infrared Sensor (TIRS) <br />OLI is visible /NIR multispectral imager<br />Supplied by Ball Aerospace and Technology Corporation<br />Two new channels compared to previous Landsats<br />Based on pushbroom imaging system<br />LDCM originally did not include TIRS<br />Added to manifest, Dec 2009.<br />
    4. 4. 4<br />TIRS High-level Overview <br />TIRS is a two channel thermal imager providing data continuity for the Landsat thermal band.<br />Pushbroom imager developed by NASA/Goddard Space Flight Center <br />TIRS operates in concert with, but independently of, OLI. <br />TIRS will produce radiometrically calibrated, geo-located thermal image data<br />TIRS will deliver algorithms and parameters necessary to evaluate data and produce required outputs <br />Final scene data generated as part of the Data Processing and Archive Segmentat the United States Geological Survey/ Earth Resources Observation and Science (EROS) facility in Sioux Falls, South Dakota. <br />USGS responsible for operational algorithms<br />OLI and TIRS data will be merged into a single data stream.<br />TIRS Delivery date is December 2011.<br />The TIRS delivery schedule is a significant driver of the overall TIRS development.<br />
    5. 5. 5<br />TIRS Science Overview<br /><ul><li>Landsat satellites have acquired single-band thermal images since 1978
    6. 6. Landsat 3 (1978 -1983 ) afforded 240 m spatial resolution in the thermal band
    7. 7. Landsat 4 (1982 - 1989) and Landsat 5 (1984 -present) afford 120 m resolution
    8. 8. Landsat 7 (1999 - present) affords 60 m resolution
    9. 9. Landsat thermal data are now used operationally to monitor water consumption on a field-by-field basis in the U.S. West and internationally
    10. 10. Evapotranspiration cools vegetation (plants “sweat”)
    11. 11. 120 meter resolution (or better) sufficient
    12. 12. Allowed by development of operational energy balanced-based evapotranspiration models
    13. 13. SEBAL, METRIC</li></ul>Using 120 m Landsat 5 Thermal Data<br />Courtesy of Richard Allen, Kimberly Research and Extension Center, University of Idaho<br />
    14. 14. 6<br />Additional TIRS Science<br />Landsat thermal data are used for:<br />• Mapping urban heat fluxes for air quality modeling (urban heat island)<br /> • Volcanic hazard assessment, monitoring, and recovery<br /> • Cloud detection and screening<br /> • Mapping lake thermal plumes from power plants<br /> • Burnt area mapping / Wildfire risk assessment<br /> • Tracking material transport in lakes and coastal regions<br /> • Identifying mosquito breeding areas and vector-borne illness potential<br />TIRS 2-Channel split window improves fidelity of surface temperatures<br />Allows correction for atmospheric effects<br />(Images from D. Quattrochi)<br />
    15. 15. Latent heat<br />(ET)<br />Sensible heat<br />(H)<br />Net radiation<br />(RNET)<br />Soil heat (G)<br />Example: Water Management Using Surface Energy Balance<br />RNET = G + ET + H<br />RNET = (SWdn – SWup) + (LWdn-LWup)<br /><ul><li> Net Radiation is the balance between incoming minus outgoing radiation
    16. 16. OLI required to calculate the SWup (short wave albedo)
    17. 17. TIRS data required to calculate the LWup from surface temperature</li></li></ul><li>8<br />Why use High Resolution Imagery?<br />Landsat vs MODIS<br />Middle Rio Grande near Albuquerque<br />60 m Landsat False Color 8/26/2002 10:33am<br />1 km MODIS False Color 8/26/2002 11:02am<br />
    18. 18. 9<br />2 channel (10.8 and 12 um) thermal imaging instrument<br />Quantum Well Infrared Photometer (QWIP) detector/FPA built at GSFC<br /><120 m Ground Sample Distance (100 m nominal)<br />185 km ground swath (15º field of view)<br />Operating cadence: 70 frames per second<br />Pushbroom design with a precision scene select mirror to select between two full aperture calibration sources<br />Onboard variable temp black body and space view<br />Passively cooled telescope assembly operating at 185K (nominal) <br />Actively cooled (crycooler) FPA operating at ≤43K<br />Thermal stability key to radiometric stability (NEDT < 0.4 K @ 300 K)<br />TIRS Instrument Overview<br />
    19. 19. TIRS Overview<br />TIRS <br />(Earthshield Deployed)<br />TIRS <br />(Earthshield Stowed)<br />Cryocooler<br />Radiator<br />Blackbody Cal<br />Radiator<br />Telescope<br />Radiator<br />Scene Select<br />Mechanism<br />Nadir <br />(Earth) View<br />Captive Earthshield<br />Latch<br />Hinge/Hinge Dampers<br />External Alignment Cube<br />Focal Plane Electronics<br />Spacecraft<br />Interface Flexures (2 of 3)<br />Interconnecting Harness Bracket<br />10<br />
    20. 20. 11<br />TIRS FOVs and Telescope Detail<br />Deployed<br />Earthshield<br />Cryocooler<br />Radiator<br />Telescope<br />Radiator<br />Scene Select<br />Mechanism<br />Nadir<br />View<br />Spaceview<br />FPE<br />Flexures<br />(1 of 3)<br />Telescope<br />Assembly<br />Cryocooler<br />
    21. 21. Thermal Design Provides Required Stability<br />12<br />Thermal Zones:<br />Warm End<br /><ul><li>Scene Select Mechanism (273-293 K)
    22. 22. Scene Select Mirror & Baffles (≤293K)
    23. 23. Stability ±1K (35 sec)
    24. 24. Stability ±2K (44Min)
    25. 25. Blackbody Calibrator (270 to 320K)
    26. 26. Stability ±0.1K (35 sec)</li></ul>Cold End<br /><ul><li>Tel Stage: Tel Assembly (185K)
    27. 27. Stability ±0.1K (35 sec)
    28. 28. Stability ±0.25K (44Min)
    29. 29. Warm Stage: FPA Shroud (<100K)
    30. 30. Cold Stage: FPA (<43K)
    31. 31. Stability ±0.01K (35 sec)
    32. 32. Stability ±0.02K (44 min)</li></li></ul><li>FPA Architecture<br />FPA has 1850 unique pixel columns<br />Corresponds to 185 km swath width<br />In-track FOV < 5.4 degrees<br />Filter band locations based on FPA<br />selection . Optimized to best region<br />on FPA.<br />35 pixel overlap<br />Between SCAs<br />FPA<br />Read 2 rows from each array for each filter and for dark region<br />Combine data on ground to get single best row<br />Row selection can be changed in flight<br />13<br />
    33. 33. TIRS Focal Plane<br />Picture of the FPA with the filters attached. Note that there are two filters over each array with a thin dark strip between them. <br />Picture of the FPA without the filters attached showing the 3 QWIPs in the center.<br />14<br />
    34. 34. TIRS on LDCM Spacecraft <br />OLI<br />Deployable Earth <br />Shield<br />(Stowed)<br />Sensor Unit<br />Connector Bulkhead<br />Cryocooler Electronics<br />MEB<br />X<br />Y<br />Z<br />15<br />
    35. 35. 16<br />Top Level Operations Concept<br />Imaging Requirements<br />400 WRS-2 scenes/24 hour period<br />Image up to 15 degrees off-nadir<br />Acquire up to 77 contiguous sun-lit scenes per orbit<br />Acquire up to 38 contiguous night scenes per orbit<br />Calibration Operations Requirements<br />Onboard calibration capability<br />Spaceview and onboard NIST Traceable Black Body<br />No calibration maneuvers required<br />No planned vicarious calibration sources<br />Orbit Requirements<br />705 km altitude<br />98.2 ± 0.015 degrees inclination<br />10:00 AM equatorial crossing descending node<br />
    36. 36. Pre-Launch Calibration Performed at GSFC<br />Calibration tests are designed to understand the sensor behavior<br />Requirement verification is necessary but not sufficient for sensor characterization<br />L 4 requirements<br />Special Characterization Test Requirements (SCTR)<br />Verify vendor-supplied test data<br />Calibration GSE requirements defined to satisfy calibration tests.<br />Calibration GSE is NIST traceable.<br />Performance measured at component, subsystem and system level.<br />17<br />
    37. 37. In Chamber Calibration Equipment<br />16” Diameter Flood source<br />Target Source Module<br />Blackbody<br />16 position motorized target wheel<br />8 position motorized filter Wheel <br />13” square steering mirror system<br />Linear stage expands effective yaw range<br />Pitch & yaw<br />Folded, all reflective, off-axis parabola collimator<br />Linear stages to move sources<br />Cooled enclosure over entire system<br />18<br />
    38. 38. Phase 1 Calibration Equipment- Acceptance at ATK – 10/2009<br />Phase 1 cal equipment includes 102 cm focal length OAP, blackbody, aperture wheel, filter wheel chopper, wiring and liquid N2 plumbing.<br />19<br />
    39. 39. Significant TIRS Hardware on Hand<br />Calibration GSE<br />EM Cryocooler<br />FPM Telescope<br />FPM FPA<br />EM FPE<br />BB SSM<br />20<br />
    40. 40. TIRS Status and Upcoming work<br />Design Finalized for all Systems<br />All Major Contracts in Place<br />Successful CDR April 27 - 30, 2010<br />Schedule, While Aggressive, is Being Met<br />Challenges Remain<br />Very active management and scrutiny<br />Active Testing/ Measurement Campaign in Progress.<br />TIRS is benefitting greatly from active support of all partners<br />Includes NASA GSFC, LDCM, USGS, NASA HQ, Orbital Systems (Spacecraft Provider) <br />