Reconstructing Forty Years of Landsat Observations
Dave Meyer, John Dwyer, Dan Steinwand, USGS The Earth Resources Observation and Science Center (EROS) Introduction Some background and history
Landsat 7 ETM+ the beginning of modern curation/management Landsat 4/5 TM extending back Landsats 1-5 MSS to the beginning Landsat Global Archive Consolidation completing the history in time and space Conceptual Framework NSLRSDA and Landsat National Satellite Land Remote Sensing Data Archive (NSLRSDA) was established in 1992 by Dept. Interior at the USGS/EROS, under direction of U.S. Congressto: maintain a permanent, comprehensive Government archive of global Landsat and other land remote sensing data for long-term monitoring and study of the changing global environment. 1996 NSLRSDA Advisory Committee subcommittee performed an assessment of geographic and temporal gaps in the Landsat record. Gaps attributable to (among many things): Govt versus private operation Practices and agreements with International Collaborators (ICs) A brief political history of Landsat
1970 1980 1990 2010 2000 LS1 LS2 LS3 LS4 LS5 LS7 LS8 MSS TM ETM+ OLI TIRS 1984 Land Remote Sensing Commercialization Act 1989 NOAA directs EOSAT to turn off LS4 & LS5 Land RemoteSensing Act of 1992 LS back to govt control 7/1/2001 Government Operations privatization era Government Operations U.S. Landsat Archive Overview (October 17, 2013)
OLI-TIRS: Landsat 8 96,929 scenes ~ 335 TB Raw and L0Ra Data average scene size 1813 MB ETM+: Landsat 7 1,648,873scenes ~ 1,531 TB Raw and L0Ra Data average scene size 487 MB TM: Landsat 4 & Landsat 5 1,770,791scenes ~ 888 TB Raw and L0Ra Data average scene size 263 MB MSS: Landsat 1 through 5 1,142,352scenes ~ 69 TB Raw and L0Ra Data average scene size 32 MB Total: 4,658,945scenes ~ 2,823 TB Raw and L0Ra Data Landsat 7 ETM+ Mission Objectives
Part of Earth Observing System (EOS) Products in standardized formats/metadata Systematic acquisitionto maximize cloud-free coverage over land surfaces Affordable (COFUR, ultimately no-cost) Calibration Absolute (incorporating in situ) Underfly with L5 for cross-platform intercalibration Precise geolocation+terrain correction Image Assessment System routinely tracks instrument/platform performance Landsat 7 Enhanced Thematic Mapper plus
1970 1980 1990 2010 2000 LS1 LS2 LS3 LS4 LS5 LS7 LS8 MSS TM ETM+ OLI TIRS SLC Failure5/31/2003 Launched 4/15/1999 ETM+ (L7) 30m: 3 VIS, 1 NIR, 2 SWIR 15m: panchromatic 60m: 1 TIR Landsat 4/5 TM Mission Objectives/Features
Introduced Thematic Mapper, continued MSS Managed by EOSAT under contract to NOAA Transferred to USGS in 1998 TM & MSS Archive Conversion System (TMACS) Consolidate and convert archive tapes from NASA, USGS at EROS Construction of FGDC-compliant metadata Landsat Archive Conversion System (earlier MSS focus) Calibration activities Reconstruction of calibration history by long term trending of gains and TOA radiance and reflectance using psuedo-invariant calibration sites (PICs) improved geolocation using ground control points and DEMs Landsat 4/5 Thematic Mapper
1970 1980 1990 2010 2000 LS1 LS2 LS3 LS4 LS5 LS7 LS8 MSS TM ETM+ OLI TIRS L5 Launched 3/1/1984 L5 TM failure 11/2011 L5 decommissioned 12/1/2012 L4 Launched 7/16/1982 L4 Terminated 12/4/1993 TM (L4-5) 30m: 3 VIS, 1 NIR, 2 SWIR 120m: 1 TIR Reconstructing L5 cal history
Dont forget thermal cal Landsats 1-5 MSS Mission objectives/features
Experimental instrument on LS1 Return Beam Vidicon (RBV) intended to be primary observation instrument Early (L1-3) recorded on analog Wide Band Video (WBV) tapes WBV recovery ( ) 21,300 HDT converted to 143 DLTs Cleaning & baking required for many orphans no scene ID, telemetry, etc TMACs included MSS from WBV Landsat 1-5 Multispectral Scanner (MSS)
1970 1980 1990 2010 2000 LS1 LS2 LS3 LS4 LS5 LS7 LS8 MSS TM ETM+ OLI TIRS MSS (L1-5) 83m: 2 VIS, 2NIR MSS Media/formats MSS-X (Landsats 1-3) MSS-P (Landsats 2-3)
MSS-X Wide Band Video tape format (WBV) No radiometric or geometric calibration applied MSS-X GSFC or CCT-X (some radiometry) MSS-X Orphan (no telemetry, acquisition date/time) MSS-P (Landsats 2-3) Radiometry + Geometry, similar to current L1G MSS-A (Landsats 2-5) Radiometry, geometric grid not applied MSS-R (Landsat 4-5, raw format) No ephemeris! MSS Orphans Data Recovery
Goal: reprocess the orphan WBVT data so that these data can be included in the EROS archive Associate orphan intervals with mission number (L1-3) and year of acquisition Infer from tape ID, supporting data, film archive Construct ephemeris and attitude support data for orphan intervals Using NORAD two-line elements for lifetime of all three instruments Assigning sensor attributes (gain state, encoding) to orphan intervals Reconstruct from calibration wedges embedded within data, pseudo-invariant targets Landsat 1 Attitude Data for 1974 L1T of Orphan MSSX Path 37 Row 23 7/11/1973 L1T of CCRS MSSX Path 37 Row 23 7/11/1973 Landsat Global Archive Consolidation (LGAC)
Started in 2010 to consolidate the Landsat archives of all stations worldwide and make all Landsat scenes available to users. Challenges: Various data formats and processing methods Unknown data formats and processing methods (stations no longer active) Media storage age and conditions Various or obsolete technologies used to ingest data While every technology asset available will be explored, some data may be irrecoverable. LGAC Historical Perspective
Over the past 35 years, over 50 ground stations have been configured to receive Landsat data Currently, there are 24 ground stations around the world that are configured to operationally receive Landsat data (19 currently active) There are an additional 9 historical collection sites operated by 7 organizations that we believe could have a significant, unique historical archive Landsat Global Archive Consolidation (LGAC)
Over 2.55 Million scenes collected as of 17 October 2013 Previous Woodcock Metric: 1,531,899 Current: 2,550,354 Previous Woodcock Metric 1,531,899 Landsat 5 TM image transcribed from CCRS D-1 tape available in archive LGAC Ingest Summary LGAC Ingest Summary Backup slides MSS Past, Present, Future
MSS Archive Conversion System (MACS) 5.0 in development (tentative release date of May 2013) Ingest, process and distribute newly acquired Landsat 5 MSS data Will eventually process the CCRS and other LGAC MSS data as well MSS Past, Present, Future
Current system cannot ingest raw serial MSS data or create products MSS Landsat Global AC Investigation began with data from Canada (CCRS) Format used by CCRS (and other stations) different Previous MSS orphan effort essential in LGAC MSS success Landsat 5 MSS Newly Acquired Began operating MSS on Landsat 5again Lessons learned/future
Landsat next? USGS NSLSRDA NASA Long-term preservation content OAIS compliance Citation/persistent identity