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Page 1
Landsat Data ProductsFree & Clear
James R. Irons
NASA Landsat Data Continuity Mission (LDCM) Project Scientist
NASA Goddard Space Flight Center
Greenbelt, Maryland 21046 USA
Thomas R. Loveland
USGS Landsat Science Team Leader
John L. Dwyer
USGS Project Scientist, LDCM Ground System
USGS Earth Resources Observation and Science (EROS) Center
Sioux Falls, South Dakota 57198-0001 USA
LDCM SRR/MDR/PNAR 22-24 April 2008
July 28, 2010 IGARSS'10, Honolulu, HI
Page 2
History of the Landsat Program
Gov’t Operations Gov’t OperationsCommercial Operations
2012
July 28, 2010 IGARSS'10, Honolulu, HI
Page 3
38-yr Landsat Data Archive
As of February 28, 2010 ETM+: Landsat 7
1,016,250 scenes 944TB Archive grows by 260 GB Daily
TM: Landsat 4 & Landsat 5 848,429 scenes 212TB Archive Grows by 40 GB Daily
MSS: Landsat 1 through 5 513,866 scenes 15 TB of Data
• Data are archived and distributed by USGS EROS Center, Sioux Falls, SD•Over 2 million scenes in the archive
July 28, 2010 IGARSS'10, Honolulu, HI
Page 4
ETM+ Scenes Archived in 2007
• Landsat 7 provides systematic coverage of the global land surface on a seasonal basis via a long term acquisition plan (LTAP)
• No other nation’s satellite system is designed or operated to achieve No other nation’s satellite system is designed or operated to achieve even even annualannual global coverage at the Landsat scale global coverage at the Landsat scale
July 28, 2010 IGARSS'10, Honolulu, HI
Page 5
Data Policy RevolutionData Policy Revolution
USGS EROS has historically distributed Landsat data products to the general public on a non-discriminatory basis at the “cost of fulfilling a user request (COFUR)”
$600 per Landsat 7 ETM+ scene
April 21, 2008 USGS Technical Announcement:
“By February 2009, any Landsat archive scene selected by a user will be processed, at no charge, automatically to a standard product recipe and staged for electronic retrieval.”
Data distribution rate increased by a factor greater than 60
EROS began distributing free Landsat data on Oct. 01, 2008
EROS distributed 1.1 M free scenes by Oct. 01, 2009 and passed 2 M scenes by March 13, 2010
– Previous annual maximum distribution was 20,000 scenes in 2001
July 28, 2010 IGARSS'10, Honolulu, HI
Page 6
Monthly EROS Landsat Data Distribution
July 28, 2010 IGARSS'10, Honolulu, HI
Page 7
Single TM/ETM+ Product Recipe
Product type: orthorectified / terrain corrected L1T - Level-1T (precision, terrain correction)
L1Gt – Level-1 Gt (systematic, terrain correction
Pixel size:15m (pan) / 30m (Vis/NIR/SWIR) / 30m (TIR) TIR pixels resampled from 120 m (TM) or 60 m (ETM+) pixels
Media type: Electronic
Output format: GeoTIFF
Map projection: UTM (Polar Stereographic for Antarctica)
Orientation: North up
Resampling: Cubic convolution
(Gap-filled Landsat 7 ETM+ data products are no longer offered)
July 28, 2010 IGARSS'10, Honolulu, HI
Page 8
Single MSS Product Recipe Product type: Level 1G (L1G)
No Terrain Correction or Ground Control
– Geographic registrations based on satellite/sensor attitude, ephemeris, and alighment data
L1T and L1Gt MSS products will be available beginning in September
Pixel size: 60 m
Resampled from 80 m pixels
Media type: Electronic
Output format: GeoTIFF
Map projection: UTM (Polar Stereographic for Antarctica)
Orientation: North up
Resampling: Cubic convolution
July 28, 2010 IGARSS'10, Honolulu, HI
Page 9
Impact of Free Data
LandTrendr: Landsat-based Detection of Trends in Disturbance and Recovery – Kennedy and Cohen, Landsat Science Team - 2010
July 28, 2010 IGARSS'10, Honolulu, HI
Page 10
May June July August September
Maintain spatial detail from Landsat, create temporal density from MODIS STARFM (Gao et al, TGARS) STAARCH (Hilker et al, RSE)
Image compositing (Landsat and MODIS) Hansen (Congo), Roy (USA)
July 28, 2010 IGARSS'10, Honolulu, HI
Fusion of Landsat and MODIS Data
Page 11July 28, 2010 IGARSS'10, Honolulu, HI
Mike WulderCanadian Forest Service
Page 12
Landsat 7 & Landsat 7 Status
Landsat 7 - 6 years beyond design life 1999 Launch Spacecraft
– Gyro 3 Failure (Shut down May 5, 2004)• Working additional improvements for software gyro
– Other Spacecraft Issues (non-critical)• Solid State Recorder – 4 memory boards • Electrical Power Subsystem – shunt #14 and shunt #6• Fuel Line Thermostat
ETM+– Scan Line Corrector Failure (May 31, 2003)– Bumper Mode Operations (April 1, 2007)
Landsat 5 - 23 years beyond design life 1984 Launch Spacecraft
– Battery 2 Anomaly (On-going) – Oct 2007 – Star Tracker Issue – June 2007– Solar Array Drive
• Fixed array operations – Aug 2006 TM
– Functioning normally in bumper-mode Current Travelling Wave Tube Amplifier (TWTA) problems
July 28, 2010 IGARSS'10, Honolulu, HI
Page 13
Future Landat Data Products
Courtesy of Orbital
The Landsat Data Continuity Mission (LDCM) is under development for a December, 2012 launch
• Developed as a NASA / USGS partnership• LDCM conducted a successful critical design review (CDR) May
25 – 27, 2010
July 28, 2010 IGARSS'10, Honolulu, HI
Page 14
Collects 400 scenes per day using pushbroom design
• Coincident with TIRS data collectionCovers a 185 km swathCollects data for nine shortwave spectral
bands• Provides continuity with seven TM and
ETM+ shortwave spectral bands• Adds two new bands
Provides a 30 m spatial resolution• 15 m panchromatic band
Collects calibration data• Internal cal lamps, shutter collects, solar
panel, lunar views, vicarious field campaigns
Courtesy of BATC
Operational Land Imager (OLI)
July 28, 2010 IGARSS'10, Honolulu, HI
Page 15
OLI & ETM+ Spectral Bands
July 28, 2010 IGARSS'10, Honolulu, HI
Page 16
Thermal Infrared Sensor (TIRS)
Collects 400 scenes per day using a pushbroom design
Coincident with OLI data collection
Covers a 185 km swath
Collects data for two long-wave spectral bands
Provides continuity with one TM/ETM+ thermal band
Provides a 100 m spatial resolution
Collects calibration data Space view, internal blackbody
July 28, 2010 IGARSS'10, Honolulu, HI
Page 17
L7 ETM+ Thermal Band LDCM TIRS Band Requirements
Band 6 60 m LWIR 10.00 - 12.50 100 m LWIR 10.30 – 11.30 Band 10
100 m LWIR 11.50 – 12.50 Band 11
TIRS and ETM+ Spectral Bands
– 120 m resolution TIRS requirement deemed sufficient to resolve most center-pivot irrigation fields in U.S. West - typically 400 to 800 m in diameter – TIRS design provides for 100 m resolution
– Landsat 4 & 5 TM’s provided 120 m thermal images for a single thermal band
– Landsat 7 ETM+ provided 60 m thermal images for a single thermal band
– A two band instrument will enable atmospheric correction so that more accurate surface temperatures can be derived.
July 28, 2010 IGARSS'10, Honolulu, HI
Page 18
Standard LDCM Data Products
LDCM standard Level-1T data products will be consistent with heritage Landsat product specifications – backward compatibility OLI and TIRS data will distributed as a combined product. Pixel
size:15m/30m/30m
Quality Assurance (QA) “band” will be included
Media type: Electronic
Product type: Level-1T (precision, terrain correction)
Output format: GeoTIFF
Map projection: UTM (Polar Stereographic for Antarctica)
Orientation: North up
Resampling: Cubic convolution
July 28, 2010 IGARSS'10, Honolulu, HI
Page 19
Bit Description Bit Description
0 Designated Fill 8 Vegetation
Confidence1 Dropped Frame 9
2 Terrain Occlusion
10 Snow/Ice
Confidence
3 <Artifact X*> 11
4 Water
Confidence
12 Cirrus
Confidence5 13
6 <Type #6
Confidence*>
14 Cloud
Confidence7 15
Bit Description
0 Designated Fill
1 Dropped Frame
2 Terrain Occlusion
3 Water**
4 Vegetation**
5 Snow/Ice**
6 Cirrus**
7 Cloud**
Confidence Levels00 = none or unset
01 = 0-33% confidence10 = 34-66% confidence
11 = 67-100% confidence
Browse image with Cloud Mask
Quality Assessment Band
• 16-bit QB rolls off of the Online Cache
with the L1 Product
• 8-bit QB available with the Full
Resolution Browse
**- Set for highest Confidence Level (11)At-launch bits
July 28, 2010 IGARSS'10, Honolulu, HI
Page 20
Desired Future Landsat Data Products
Surface Reflectance / Temperature Products Example – using the LEDAPS ((Landsat Ecosystem Disturbance
Adaptive Processing System) of Masek et al.– Based on MODIS/6S radiative transfer approach
• water vapor from NCEP re-analysis data
• ozone from TOMS, EP-TOMS
• topographic-dependent Rayleigh correction
• Aerosol optical thickness estimated from imagery using the Kaufmann et al (1997) “Dense, dark vegetation” approach
Essential Climate Variables Land Cover Land Cover Change Biomass
July 28, 2010 IGARSS'10, Honolulu, HI
Page 21
Atmospheric Correction
1990’s Landsat-5 mosaic
100 km
100 km
TOA reflectance
Surface reflectance
BOREAS Study Region100 km
July 28, 2010 IGARSS'10, Honolulu, HI
Page 22
LEDAPS Forest Disturbance (1990-2000)
0 >40
% 5km cell disturbed
Masek et al., RSE, 2008
MODIS forests
July 28, 2010 IGARSS'10, Honolulu, HI
Page 23
Conclusion The USGS policy of free Landsat data distribution is fostering
rapid advancements in the capacity and capability to map land cover and land use change (e.g. forest disturbance) over multiple decades on a global scale for climate and carbon research
Free and open data policies are the first step towards community remote sensing and a global earth observation system of systems New Landsat data policy followed by recent, welcome ESA
announcement of free GMES / Sentinel-2 data policy at Living Planet Symposium
Enables projects such as the Group on Earth Observations (GEO) forest carbon tracking initiative
The Landsat Data Continuity Mission (LDCM) will be the first Landsat satellite launched into the era of free data LDCM will continue the legacy of global Landsat data collection with free
and open data distribution by USGS
July 28, 2010 IGARSS'10, Honolulu, HI