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Landsat Data Characteristics and Holdings

Landsat Data Characteristics and Holdings. July 30, 2012 Presented By: Keith Alberts USGS Landsat Ground System Lead. Landsat Mission. Ensure collection of consistently calibrated Earth imagery

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Landsat Data Characteristics and Holdings

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  1. Landsat Data Characteristicsand Holdings July 30, 2012 Presented By: Keith Alberts USGS Landsat Ground System Lead

  2. Landsat Mission • Ensure collection of consistently calibrated Earth imagery • Provide long term, repetitive observations of the Earth’s land mass, coastal boundaries, and coral reefs • Detect and characterize natural and human induced change

  3. Satellites • Satellite Performance • Landsat 5 continues to provide data after 28 years in orbit! • Landsat 5 design life expectancy was only 2-3 years • Over 1.2 million scenes in the U.S. archive • Landsat 7 began 14th year in orbit on April 15, 2012! • Landsat 7 design life expectancy was only 5 years • Over 1.5 million scenes in the U.S. archive • Continued coverage for International Stations (currently 4 stations)

  4. Landsat Reception Network

  5. Landsat 5 Flight Segment • HIGH GAIN ANTENNA • 8/85 Transmitter A failure • GPS ANTENNA • Not Operational • MULTI-SPECTRAL SCANNER • 8/95 Band 4 failure • COMM & DATA HANDLING MODULE • Located back side of s/c OMNI ANTENNAS • ACS MODULE • 07/03 FHST#1 Degradation • Skew wheel tack anomaly 10/92 • 11/92 Earth Sensor 1 failure • 02/02 Earth Sensor 2 failure • Intermittent operations possible • SOLAR ARRAY DRIVE / PANELS • 01/05 Primary Solar Array Drive failure • Nominal Solar array panel degradation (12/04) • 11/05 Redundant Solar Array Drive Malfunction COARSE SUN SENSORS • PROPULSION MODULE • 3/84 Primary Thruster D failure • POWER MODULE • 05/04 Battery 1 failure / Removed from power circuits • 10/07 1 of 22 Cells fails on Battery #2 • WIDEBAND COMM. MODULE • 07/88 Ku-band TWTA Prime failure (OCP) • 07/92 Ku-band TWTA Redundant failure (OCP) • 08/87 X-band TWTA Prime failure (OCP) • 03/06 X-band TWTA Redundant Anomaly X-BAND ANTENNA • THEMATIC MAPPER • 10/94 Power Supply 1 stuck switch • 06/02 TM switched to bumper mode • DIRECT ACCESS S-BAND • 03/94 Side A FWD Power Sensor failure

  6. Landsat 7 Flight Segment Electrical Power System Enhanced Thematic Mapper + Batteries: Solar array: •5/31/2003 SLC Failure •4/01/2007 SAM -> Bumper mode •5/31/2003 SLC Failure Performance nominal • 5/14/2002 Circuit #14 Failure • 5/16/2005 Circuit # 1 Failure • 14 circuits remain operating • No impact to ops Reaction Control System • 1/07/04 Fuel line #4 thermostat #1a failure. • 2/24/05 Fuel line #4 thermostat #1b failure • Thermostat 2a shows signs of failure • No impact to ops; extended plan in place Attitude Control System •05/05/2004 Gyro 3 Shut Off •Singe gyro control system in development Solid State Recorder • 11/15/1999 SSR PWA #23 Loss • 02/11/2001 SSR PWA #12 Loss • 12/07/2005 SSR PWA #02 Loss • 08/02/2006 SSR PWA #13 Loss • 03/28/2008 SSR PWA #22 Loss • Each PWA is ≈4% loss of launch capacity • Boards are likely recoverable • 09/03/2006 SSR PWA #23 Recovered X-band System S-band System Performance nominal Performance nominal

  7. U.S. Landsat Archive Overview (July 2, 2012) • ETM+: Landsat 7 • 1,420,626scenes • ~1,319 TB Raw and L0Ra Data average scene size 487 MB • TM: Landsat 4 & Landsat 5 • 1,277,915 scenes • ~641 TB Raw and L0Ra Data average scene size 263 MB • MSS: Landsat 1 through 5 • 608,642 scenes • ~37 TB Raw and L0Ra Data average scene size 32 MB • Total: • 3,307,183 scenes • ~1,997 TB Raw and L0Ra Data

  8. Changes to Operations Concept • Processing and Distribution Systems • Major operations concept shift (began with a pilot in FY07) to “Web-enable” the Landsat archive • ALL Landsat products are now distributed to users via the internet at no cost • No media distribution option is available • Users could previously select from many processing parameters – only one set of parameters is now available • Over 10% of the archive (>350,000 scenes) are processed, stored on-line, and available for immediate download • All other data are available for “on-demand” processing

  9. Downloads

  10. Whoareour users? • 180+ countries

  11. What are they doing?

  12. Where in the World?

  13. Fun Fact • Scene most downloaded in April 2012 • California Coastline • TM, P45:R33 • Acquired Oct. 2011

  14. Landsat Data Distribution Concept • Process and Distribute data freely to users • Process new data (currently <100% cloud cover) automatically for immediate download and retain on ftp server for approximately 3 months • Process requests on-demand for older data • Single Processing Parameter Recipe • Pixel size: 15m/30m • Media type: Download only • Product type: L1T (precision- and terrain-corrected) • Output format: GeoTIFF • Map projection: UTM • Orientation: North up • Resampling: Cubic convolution

  15. LandsatLook • Band combinations • OLI: 6,5,4 • ETM+ & TM: 5,4,3 • MSS: 2,4,1 • Data values • Top of Atmosphere Reflectance • Image format • 3-band RGB JPEG • Georeference information in World & GDAL XML file • JPEG and georeference files zipped for download • File size is approximately 5 MB • Pixel size is retained

  16. TM & ETM+ Natural Color LandsatLook • GLS 1975Landsat 1: 23 Feb 1973Bands 241 • TOA reflectance • GLS 2006Landsat 5: 13 Jun 2005Bands 543 • TOA reflectance

  17. TM & ETM+ Thermal LandsatLook 2% clip with linear stretch • Band 6 • TOA Brightness Temperature Craters of the Moon, Idaho Landsat 5 TM 10 July 1996 Llaima Volcano, Chile Landsat 7 ETM+ 18 April 2009

  18. Landsat Standard Product Evolution • Improve registration • Ground Control Point analysis – seasonal, historical, stable • Increase percentage of L1T • Independent verification of geometry • Increase archive • Orphan and Global Archive Consolidation • Improve metadata • Land ACCA score • Level 1 searchable and product metadata • Product integration with Landsat 8 • GIS-ready visual product • TOA reflectance • Cloud/quality band • Data access • Increase number of images online • Decrease on-demand lag time • Continue to provide best possible geometry and radiometry

  19. Verification of Geometric Accuracy An example JPEG image along with Product Path/Row : 128/18 (WRS-1) Legend : Green - RMSE <= 0.5 pixel Cyan - 0.5 < RMSE <= 1 pixel Blue - 1 < RMSE <= 2 pixel Yellow - 2 < RMSE <= 3 pixel Red - RMSE > 3 pixel GVERIFY_RMSE : 0.57 pixels

  20. Landsat MSS Orphans • What is an MSS Orphan? • Intervals of L1-3 data that are missing ephemeris information (scene center, lat/lon, spacecraft atitude, sun elevation/azimuth, sensor gain, etc.) • Ephemeris data store on separate tape (9-track) during that era • Completed recovery of the orphan data! • Over 170,000 full scenes recovered • 106,335 NEW scenes added to the US archive

  21. Landsat Global Archive Consolidation: Goals & Assumptions • Consolidate Landsat Acquisitions from all ground stations into a single consistently calibrated, georegistered, formatted, and documented global archive that will be shared at no cost and with no restrictions to the global user community • Often unknown physical organization, radiometry and geometry • Often Orphan-like - data unpacking, framing challenges, etc. • Some may be partially processed causing a calibration challenge. • Orphan, MSS, Cross-calibration, and Gaussian Pyramid research greatly assist the LGAC activity. • Over 771,000 full scenes added to the archive so far • Over 385,000 are unique!

  22. Distribution of LGAC data in Archive

  23. LGAC: Status

  24. Global Landsat Survey Coverage 1975 1990 2000

  25. GLS1990 • Original survey • 7,400 scenes • Received processed data, then re-processed to a similar format • Requires reprocessing • Raw data requested from ICs • Expect over 95% of original scenes • Update radiometry and geometry

  26. GLS2010

  27. Landsat 7 LTAP constraints • Acquire 400/day with continued cooperation with ICs to increase acquisitions • ETM+ duty cycle • Number of download opportunities and solid state recorder management • SLC-off: image pair

  28. Landsat 7 16-day cycle

  29. Where can I get Data? http://glovis.usgs.gov/ http://earthexplorer.usgs.gov/ http://landsatlook.usgs.gov/ More Information http://landsat.usgs.gov/ EarthNow! Image Viewer http://earthnow.usgs.gov/

  30. Thank You! Questions?

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