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Landsat Data Gap Study TeamBriefing

Study Team Chairs:

Ed Grigsby, NASA Garik Gutman, NASA Ray Byrnes, USGS

Team Lead:Vicki Zanoni, NASA

20 May 05

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Outline

• Introduction• Key Findings• Background• Data Gap Study Team• Assumptions• Requirements• Capabilities• Comparison of Capabilities with Requirements• Conclusions• Recommendations

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Introduction

• The Landsat Program provides for and updates a national archive of land remote sensing data for distribution to the U.S. Government, international community, and the general public– Public Law 102-555, the Land Remote Sensing Policy Act of

1992– Presidential Decision Directive/NSTC-3 (5/5/94; amended

10/16/00)– Management Plan for the Landsat Program

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Introduction

• The Earth observation community is facing a probable and pending gap in Landsat data continuity before OLI data arrive in 2010 – Landsat 5 limited lifetime/coverage– Degraded Landsat 7 operations; potential failure in 2007– Either or both satellites could fail at any time: both beyond design life

• Urgently need strategy to reduce the impact of a Landsat data gap– Landsat data are used extensively by a broad and diverse community– A data gap will interrupt a 33-yr time series of land observations during

a critical time period

• Landsat Program Management must determine utility of alternate data sources to lessen the impact of the gap and feasibility of acquiring data from those sources in the event of a gap

• A Landsat Data Gap Study Team, chaired by NASA and the USGS, has been formed to analyze potential solutions

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Key Findings

• The Landsat Program is unique– Single source of systematic, global land observations– Alternate sources can reduce the impact of a Landsat data gap

• Data quality of potential candidate systems is unverified; however, based on preliminary analysis– India’s ResourceSat and China/Brazil’s Earth Resources Satellite (CBERS)

are the leading candidates for reducing the impact of a Landsat data gap • Potentially acceptable global acquisition capability, availability, spatial and spectral

coverage• Landsat data gap mitigation efforts could serve as GEOSS prototype

– Implementation plan correlates with the GEOSS Global Land Observing System – Land Use/Land Cover Change Initiative

• Several systems could meet special regional acquisition needs during some or all of the data gap period

– ASTER (U.S. and Japan)– U.S. Commercial Satellites– SPOT (France)– EO-1/ALI (U.S.)

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Landsat Importance to Science • Change is occurring at rates Change is occurring at rates

unprecedented in human historyunprecedented in human history

• The Landsat program provides The Landsat program provides the the onlyonly inventory of the global inventory of the global land surface over time land surface over time – at a scale where human vs. natural at a scale where human vs. natural

causes of change can be causes of change can be differentiateddifferentiated

– on a on a seasonalseasonal basis basis

• No other satellite system is No other satellite system is capable/committed to even capable/committed to even annualannual global coverage at this global coverage at this scalescale

1986

1997

Amazonian Deforestation

100 km Courtesy TRFIC–MSU, Houghton et al, 2000.

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Landsat Impacts all GEOSS Societal Benefit Areas

Natural & Human Induced

Disasters

Human Health & Well-Being

Energy Resources

Climate Variability & Change

Water Resources

Weather Information, Forecasting & Warning

Terrestrial, Coastal

& Marine Ecosystems

Sustainable Agriculture &

Desertification

Biodiversity

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Landsat 7 ETMLandsat 7 ETM++ U.S. Global Archive and Distribution U.S. Global Archive and Distribution

Interest in Landsat data is truly global

Landsat 7 International Ground Station Network - November 2004

Number of Scenes Distributed

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Landsat and the NASA Science and Applications ProgramsLandsat and the NASA Science and Applications Programs

• Over the past five years NASA research programs have supported over 200 science and applications projects that use Landsat data

• NASA projects support a number of national and international programs and projects that rely on or require Landsat data

– U.S. Climate Change Science Program– North American Carbon Program– President Bush’s Initiative on Illegal Logging– Global Observations of Forest Cover and Land Dynamics (GOFC-GOLD) project of GTOS– GEOSS (Global Earth Observation System of Systems)

• Strategic Plans for GEOSS and the U.S. Integrated Earth Observation System cite Landsat as an important asset

• NASA Information Technology Projects have distributed over 2 million Landsat data products since 1998 (e.g., TRFIC at Michigan State U. and GLCF at U. of Maryland).

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AVHRR/MODIS

• spatial resolution 15m, 30m, 90m

2048 km swath

183 kmLandsat

• spatial resolution, 250m, 500m, 1000m

• spatial resolution, 15m, 30m

• global coverage, 2 days

• 16 day orbital repeat• seasonal global coverage

Landsat's Role in Terrestrial Remote Sensing

~ 10 km• spatial resolution ~ 1m • global coverage, decades, if ever

Commercial Systems

ASTER 60 km• 45-60 day orbital repeat• global coverage, years

MISR• spatial resolution, 275m, 550m, 1100m

360 km

• global coverage, 9 days

3300 km swathVIIRS

• spatial resolution, 400/800m (nadir (Vis/IR)) • global coverage, 2x/day/satellite

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Value of Landsat Continuity

• The value of Landsat goes The value of Landsat goes beyond sensor performance:beyond sensor performance:

• Long-term data archiving, Long-term data archiving, global data acquisition global data acquisition strategy, open data policy, and strategy, open data policy, and commitment to data continuitycommitment to data continuity

• USGS preserves a 33-yr USGS preserves a 33-yr archive of Landsat data: no archive of Landsat data: no other nation is committed to other nation is committed to acquiring, maintaining, acquiring, maintaining, preserving, and extending a preserving, and extending a global archive of land global archive of land observationsobservations

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Landsat Data Gap Study Team

Objective• Recommend options, using existing and near-term capabilities, to store,

maintain, and upgrade science-quality data in the National Satellite Land Remote Sensing Data Archive

– Consistent with the Land Remote Sensing Policy Act of 1992

Approach• Identify data “sufficiently consistent in terms of acquisition geometry, spatial

resolution, calibration, coverage characteristics, and spatial characteristics with previous Landsat data…”

– Consistent with Management Plan for the Landsat Program

Process• Identify acceptable gap-mitigation specifications• Identify existing and near-term capabilities• Compare capabilities to acceptable specifications• Synthesize findings and make recommendations

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Team MembershipEdward Grigsby, NASA HQ, Co- ChairRay Byrnes, USGS HQ, Co- ChairGarik Gutman, NASA HQ, Co- ChairJim Irons, NASA GSFC, Community Needs Working Group LeadBruce Quirk, USGS EDC, System Capabilities Working Group LeadBill Stoney, Mitretek Systems, Needs-to-Capabilities Working Group LeadVicki Zanoni, NASA HQ Detail, Team Coordinator and Synthesis Working Group

Lead

Mike Abrams, JPLBruce Davis, DHS (NASA detailee)Brad Doorn, USDA FASFernando Echavarria, Dept. of StateStuart Frye, Mitretek SystemsMike Goldberg, Mitretek Systems Sam Goward, U. of MarylandTed Hammer, NASA HQChris Justice, U. of MarylandJim Lacasse, USGS EDC

Martha Maiden, NASA HQDan Mandl, NASA GSFC Jeff Masek, NASA GSFCGran Paules, NASA HQJohn Pereira, NOAA/NESDISEd Sheffner, NASA HQTom Stanley, NASA SSCWoody Turner, NASA HQSandra Webster, NGADiane Wickland, NASA HQDarrel Williams, NASA GSFC

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Assumptions (1)

• Focus on data acquisition solutions– NOT spacecraft development

• Address DoI (USGS) responsibility for preserving and populating the National Satellite Land Remote Sensing Data Archive (NSLRSDA)

– Other organizations (e.g., USDA and NGA) are able to procure alternate source data, but have no mandate to archive, preserve, distribute, or share the data

• Assume 2007 Landsat 7 failure for purposes of planning and budgeting

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Assumptions (2)

• Landsat 5 has limited lifetime and capability– 21years on orbit (3-yr. design life); Fuel depletion in 2009– Direct downlink only; precludes global coverage

• OLI data available no earlier than 2010

• LDCM data specification used to define data quality and quantity goals

– Study team recognized inability to meet all goals given capabilities of alternate data sources

• Landsat 7 unrestricted data policy will serve as the model for acquired data rights

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Requirements Analysis

• LDCM Data Specification (“Goal”) has been vetted by science and applications communities, and supports the range of Landsat applications

• Obtaining data identical to LDCM from existing systems is not possible

• Acceptable specifications were derived to support basic global change research given available sources of Landsat-like data:– Global mapping of land-cover– Long-term analysis of land-cover change

• Analysis incorporated OSTP Landsat User Survey Responses– Users require Landsat-like data (global coverage, moderate resolution,

spectral coverage)– Many users already considering alternate sources of data following

Landsat-7 Scan Line Corrector anomaly

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Acceptable Specifications: Radiometry, Geometry

PerformanceParameter

Performance Goal: LDCM Specification Acceptable Specification*

Radiometry

<5% error in at-sensor radiance, linearly scaled to image data

<15% error in at-sensor radiance, linearly scaled to image data

Spatial Resolution30m GSD VNIR-SWIR; 15m panchromatic 100m GSD

Geographic Registration <65m circular error <65m circular error

Band-band registrationuncertainty <4.5m (0.15 pixel) uncertainty <0.15 pixel

*Acquired data must be characterized and verified against these specifications to ensure data quality and continuity.

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Acceptable Specifications: Spectral Coverage

Performance Parameter

Performance Goal: LDCM Specification

Acceptable Specification

Spectral Bandpass (nm)

Blue 433-453  

Blue 450-515  

Green 525-600  

Red 630-680 √

NIR 845-885 √

SWIR 1560-1660 √

SWIR 2100-2300  

SWIR 1360-1390  

Pan 500-680  

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Acceptable Specifications: Global Coverage

GlobalCoverage

Performance Goal:LDCM Specification

• Seasonal (4X annually), substantially cloud-free global acquisition •Includes U.S. acquisition every 16 days

• Global, substantially cloud-free acquisitions twice per year (2 seasons annually)

Acceptable Specification PerformanceParameter

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Capabilities Analysis

• Team focused on systems that can best meet acceptable specifications– Used publicly available information to make this determination– Low and high resolution systems were not the initial study focus

• High resolution systems cannot meet global coverage acceptable requirement; might be source for sub-global sampling sites

• Low resolution systems cannot meet spatial resolution acceptable requirement

• Informal inquiry of commercial and foreign data providers to identify global acquisition capabilities and associated data cost estimates

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• IRS ResourceSat – 1, 2 (India)• CBERS – 2, 2A, 3, 4 (China & Brazil)• RapidEye – 1, 2, 3, 4, 5 (Germany)• DMC – Algeria, Nigeria, UK, China• Terra/ASTER (METI & NASA)• High-resolution U.S. commercial systems

– IKONOS– QuickBrid– OrbView-3

• SPOT – 4, 5 (France)• ALOS (JAXA)• EO-1/ALI (NASA & USGS)

Systems Considered

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Comparison of Capabilities with Requirements

*Data quality is acceptable if verified to meet acceptable specifications for radiometric and geographic accuracy and band-to-band registration

Global Spatial Spectral Data Data

99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 Coverage Res. Coverage Quality Cost

ResourceSat-1 OK OK OK ? OK

ResourceSat-,2 OK OK OK ? OK

CBERS 2 ? OK OK ? ?

CBERS 2A ? OK OK ? ?

CBERS 3 ? OK OK ? ?

CBERS 4 ? OK OK ? ?

RapidEye 1,2,3,4,5 OK OK X ? ?

Terra/ASTER X OK OK OK ?

EO-1/ ALI X OK OK OK ?

SPOT 4 ? OK OK OK ?

SPOT 5 ? OK OK OK ?

ALOS ? OK X ? ?

DMC Algeria OK* OK X ? ?

DMC Nigeria OK* OK X ? ?

DMC UK OK* OK X ? ?

DMC China OK* OK X ? ?

OK MEANS

Global Coverage Two times (leaf on, leaf off) global coverage per year * DMC coverage requires 3 operating satelites

Spatial Resolution Better than 100 meter resolution DESIGN LIFE

Spectral coverage 3 VNIR plus 1 SWIR band (X means no SWIR band) ACTUAL LIFE + CURRENT TECHNICAL PROJECTION

Data Quality

Data Cost Reasonable relative to current Landsat data costs

Meets min. rqmt. for radiometric and geographic accuracy and band-to-band registration (slide 16)

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Conclusions (1)• The Landsat Program is unique

– Single source of systematic, global land observations– Alternate sources can reduce the impact of a Landsat data gap

• Data quality of potential candidate systems is unverified, however, based on preliminary analysis

– India’s ResourceSat and China/Brazil’s Earth Resources Satellite (CBERS) are the leading candidates for reducing the impact of a Landsat data gap

• Potentially acceptable global acquisition capability, availability, spatial and spectral coverage

• This effort could serve as a GEOSS prototype for International cooperation:– Implementation plan correlates with the GEOSS/Global Land Observing

System/Land Use/Land Cover Change initiative• System of systems• Building upon existing systems• Continuity of observations• Full and open exchange of Earth observations• Data quality and cross-calibration • Data management standards• Interoperability

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Conclusions (2)

• Several systems could meet special regional acquisition needs during some or all of the data gap period

– ASTER (U.S. and Japan)– U.S. commercial systems (sampled)– SPOT (France)– EO-1/ALI (U.S.) (sampled)

• Key expectations may not be met during a data gap– Data continuity / consistency– Seasonal coverage– A reliable “gold standard” for sensor cross-calibration – Rapid data acquisition and access for emergency response– Acquisition and access to data for internationally sensitive areas for

national/homeland security– Directly downlink to international ground stations– U.S. 16-day repeat coverage – Price of data

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Conclusions (3)

• There will be programmatic challenges:

– Data cost and licensing

• Commercial prices for global coverage and/or license restrictions could be prohibitive• Preference is for government-to-government sharing of data or systems

– Negotiations with foreign providers and U.S. commercial companies:

• ResourceSat: Indian Remote Sensing (IRS) and/or Space Imaging

• CBERS: China and Brazil

• ASTER, ALOS: Japan

• SPOT: Spot Image Corporation and Terra Image and/or ScanEx

– Uncertainty in system lifetimes and operational concepts

• Terra/ASTER: continued Terra operations under consideration by NASA

• RapidEye: entire constellation to be launched on one vehicle

• EO-1/ALI: probable operations through FY06

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Conclusions (4)

• There will be technical challenges:

– Receiving and archiving data from new source(s)

• Different formats, storage media, metadata

• Cataloguing data acquired along different orbits with varying scene sizes and swath widths

– Data characterization and cross-calibration

– Analysis/Applications of data from new source(s)

• Mosaicking and co-registering data from multiple sources with different spatial resolutions, registration accuracy, and scene size

• Differentiating land cover change from data discrepancies

• Developing new methodologies and algorithms incorporating data from multiple sources

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RecommendationsImmediate Action Plan

• U.S. civil agencies (led by NASA, NOAA, USGS) to:

– Verify data quality of candidate data sources:

• Complete initial analysis of ResourceSat and CBERS data sets and system capabilities

– If data quality and volume are found sufficient for Landsat-like data continuity, explore agreement (s) to

acquire, archive, and distribute data

• Further investigate other global and regional coverage candidates to better define technical

capabilities, costs of data, and accessibility (SPOT, Rapid Eye, U.S. commercial firms, etc.)

– Estimate budget impact for FY07-10

– Conduct data characterization, calibration, and science validation assessments on

candidate data sources

– If funding is available, extend operations of Landsat-like Terra/ASTER, EO-1/ALI

systems to provide immediate data insurance if L7 fails early

• Data quality and usefulness, costs well documented

• USGS already ingests, archives, distributes data

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RecommendationsNear-Term Action Plan

• U.S. civil agencies coordinate data gap mitigation efforts with U.S. Group on Earth Observations

– Correlate with GEOSS-Global Land Observing System Land Use/Land Cover Change elements

– Complete detailed planning for International Cooperative GEOSS/GLOS/LULCC Initiative

– NASA, NOAA, USGS coordinate on agency-unique capabilities

– Develop plan-of-action for the compilation, validation and sharing of global land data sets:

• 2-yr: complete plans, processes, procedures, models, international agreements, etc.

• 6-yr: produce 2010 GLOS GeoCover data set (positionally accurate images of the Earth’s land cover, as in 2000 GeoCover product)

• 10-yr: produce 2015 GLOS GeoCover data set (including OLI data)