17 May 2015

U.S. Department of the InteriorU.S. Geological Survey

Gregory StensaasUSGS EROS Center

USGS Report to GSICS EP-16

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GSICS USGS Point of Contact• USGS POCs for EP and Working GroupsGregory L. StensaasProject Manager, Remote Sensing Technologies and National Land Imaging RequirementsUS Geological Survey (USGS), Earth Resources Observation and Science (EROS) Center, 47914 252nd Street Sioux Falls, SD 57198Phone: Voice 605-594-2569, Cell: 605-321-8793Email: stensaas@usgs.gov

Ron MorfittUSGS Landsat Calibration LeadUS Geological Survey (USGS), Earth Resources Observation and Science (EROS) Center, 47914 252nd Street Sioux Falls, SD 57198Phone: Voice 605-594-2688, Email: rmorfitt@usgs.gov

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Overview

• Landsat Observatory statuses• Requirements• National Earth Observation Assessment (EOA)• Instrument performance and anomalies• Future Landsat• Land Product Characterization System (LPCS)• Imagery Assessments• Future Collaboration

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42+ Years of Continuous Landsat Global Land Observation• Landsat 1 was launched July 23, 1972 (MSS)• Landsat 2 was launched January 22, 1975 (MSS)• Landsat 3 was launched March 5, 1978 (MSS)• Landsat 4 was launched July 16, 1982 (TM)• Landsat 5 was launched March 1, 1984 (TM)• Landsat 6 was launched October 5, 1993, but never reached orbit• Landsat 7 was launched April 15, 1999, May 2003 SLC-Off (ETM+)• Landsat 8 launched February 11, 2013 (OLI, TIRS)

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Landsat Operational Satellite StatusLandsat 7• Collecting about 475 new scenes per day; about 22% of pixels

missing per scene (faulty scan-line corrector)• L7 collection strategy modified to concentrate on continental

coverage; L8 capturing islands and reefs• Sufficient fuel for a few more years of operation; limited subsystem

redundancy

Landsat 8• Collecting approximately 725 new scenes per day; supports 8-day

revisit cycle• An anomaly in the electronics associated with the Thermal Infrared

Sensor (TIRS) has been under investigation while normal optical imaging operations continued with the Operational Land imager (OLI)

• Thermal imaging was recently suspended while the Flight Operations Team switched over to redundant circuitry; normal thermal imaging resumed following recalibration of TIRS

• Working a stray light issue (ghosting) on TIRS – solutions being worked

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Active Landsat International Ground Stations10 Active L7 Stations 17 Active L8 Stations

L7 pLGN

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Operational Land Imager (OLI) & Thermal Infrared Sensor (TIRS) Spectral BandsDesigned for Continuity…

Whiskbroom (Landsat 1-7)

Pushbroom (Landsat 8)

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Significant Improvements to Landat-8• More image data –

• 40 year record is extended to 45-50 years, or more• more coverage – 700 scenes/day vs. 250 scenes/day with L7• 100% of data collected goes to the US archive each day vs. ~40% with L7

• Better image data – provides greater sensitivity to detect changes in surface properties• 5x improvement in signal to noise ratios (SNR)• 12 bit quantization (256 vs 4096)• Improved cartographic accuracy due to advanced L8 geo-location

capabilities• New measurements – and new applications

• Coastal aerosol band (0.433–0.453 μm) – detection of water column constituents (e.g., chlorophyll, suspended materials)

• Cirrus band (1.360–1.390 μm) – improves overall image quality because of better cloud screening

• Additional thermal band – improves accuracy and precision of temperature measurements

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0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

2008 2009 2010 2011 2012 2013 2014

Landsat Scenes Downloaded from USGS EROS Center3

(Cumulative)

Free and open data policy

Before the free data policy, the USGS distributed approx. 20,000 Landsat scenes/year. In the last 6 months alone (Mar-Aug 2014), the USGS distributed over 5 million Landsat scenes; the rate of downloads is still increasing.The free data policy is relatively new, but Landsat is already critical to many operational applications.• Landsat ranked 3rd “most critical” of 362

observing systems in the National Plan for Civil Earth Observations largely because it’s relied on in almost every societal benefit area. 1

• In 2012, 2/3 of users self-identified as “research”, 1/3 as “operational. Operational users were most dependent on Landsat.2

• 1/4 of users relied completely on Landsat. For 3/4 of users, Landsat was the major data source. 2

• 62% of respondents said if Landsat data were no longer available, they would need to discontinue some of their work. 2

1 OSTP 2014, National Plan for Civil Earth Observations2 Miller and Serbina 2013, Landsat user survey3 Includes only downloads from the USGS EROS. (Google Earth delivers approximately 1 billion Landsat scenes to users per month.)

Users and uses are rapidly increasing

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Users depend onfundamental Landsat requirements• Long-term continuity and long term acquisition plans

o Commitment to consistent global coverage, including polar regions, islands, and reefs. E.g.o Gallo can transfer its Landsat-based vineyard management to its global

properties.o Global coverage includes coastal and ice shelf conditions, ash plumes, and

indications of reef die-off or recovery.*• Free data policy

o Impact on technology sector: Since the free data policy, the Landsat archive has inspired Google Earth, Google Earth Engine, Esri Change Matters, etc.

o Impact on science: Hansen et al. (2013, Science) published a first-ever global forest change study using >654,000 Landsat scenes and Google Earth Engine. Would have cost ~$392M without the free data policy.

• Continuity and all Landsat data orthorectified and calibrated to a common radiometric standardo Permits comparison across the 42+ year instrument record, from Landsat 1 to the

present.• Coincident optical and thermal data

o Two-thirds of users requiring thermal infrared data also require coincident optical datao E.g. agricultural users assess both evapotranspiration and vegetation status

• 8-day repeat data collectiono To ensure adequate frequency of cloud-free imagery to monitor agricultural productivity and

vegetation condition

*Strong, A. E., et al. "Enhanced satellite remote sensing for coral reef management: Next decade." Proceedings of 12th International Coral Reef Symposium A. Vol. 5. 2012.

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National Plan for Civil Earth Observations (July 2014)

• First-of-its-kind interagency-coordinated Plan

http://www.whitehouse.gov/blog/2014/07/18/harnessing-observations-and-data-about-our-earth

• Based on government-wide assessment of the Nation’s Earth Observations portfolio

• Led by OSTP via US Group on Earth Observations, to be revised every 3 years

• USGS Requirements Capabilities & Analysis for Earth Observations (RCA-EO)

• http://remotesensing.usgs.gov/rca-eo/• USGS and NOAA jointly developed Earth

Observation Requirements Evaluation System (EORES) and portfolio assessment processes used to support EOA-2012

• USGS EORES is supporting all Civil EO requirements for the EOA 2016

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Landsat-7 Geometric PerformanceGeodetic accuracy improved

since 2012

Bumper mode parameters continue to be updated ~2 weeks

Mirror velocity surpassed Landsat-5

TM velocity

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Landsat-7 Radiometric Performance• Lifetime TOA reflectance based on

PICS stable with seasonal variations• Coherent noise component continues to

increase• Continuing quarterly ETM+ absolute gain

updates• Planning to propagate L8 OLI reflectance

based calibration to L1-7

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Landsat-8 Geometric PerformanceGeodetic performance

well below spec

Spatial performance closer to aliasing limit than blur

Band-to-Band registration typically less than 3m

Less than 17m OLI-to-TIRS

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Landsat-8 Radiometric Performance

• SNR continues to exceed requirements

• Continuing quarterly relative gain updates

OLI radiometric stability, worst case band, about 1% over 2

years; most bands ~0.3%

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Lunar calibration with L-8

@ >30 pixels from edge0.14%

@15 pixels from edge0.25% of lunar signal

@5 pixels from edge 0.53% of lunar signal

From Raviv Levy

Lunar image CA band

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TIRS Stray Light Correction Results(Preliminary)

Original GOES Correction TIRS Correction

Model of stray light determined by optical model Effectively a point spread function for

each detector Verified by comparing PSF to special

lunar scans

Method 1: Convolves PSF with GOES

imagery to estimate stray light per pixel in TIRS image

Subtract stray light estimate from TIRS image

Method 2: Convolves PSF with TIRS

imagery, scene before and after Where no TIRS imagery, use

nearest TIRS pixels Subtract stray light estimate from

TIRS image

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SLI Future Missions

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Continuing Imagery Assessments• Assessments:

• ResourceSat-2 AWiFS-2, VNREDSat-1, KOMPSAT-3, WorldDEM™, PROBA-V, Planet Labs (Doves-3 & 4, Flock-1a, Flock 1-c), SkyBox-1 & 2, SPOT-7

• Future assessments:• More Planet Labs satellites, CBERS-4, KompSat-

3A, DMC-3 constellation• Higher-Level Product Quality Monitoring• Follow-on satellites, or pairs, are very similar

• AWiFS-1/AWiFS-2, Pleiades-1a/-1b, SPOT-6 & 7, etc.

• Sentinel-2 Cross calibration• NOAA - VIIRS, GEOS-R, JPSS

Planet Labs Image over NYC07 Sep 2014

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Continuing to add geometric, spatial and radiometric test sites

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Future Contributions to GSICS• Continue to support GSICS EP• Provide additional support to Working Groups in the

future• Support Worldwide Calibration and Validation Test

Sites• Updates and comments welcome• Working on spatial res. RER/MTF test site catalog

• Continuing cross calibration and trending efforts• Low – High Resolution systems

• Developing an LPCS tool and beginning to compare CDRs and products

• Interested in user requirement vs. system solutions gathering and analysis

Questions&

Backup Slides

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Attitude Control System

X-band System S-band System Performance nominal

Enhanced Thematic Mapper +

BatteriesPerformance nominal

Solid State Recorder

Reaction Control System•1/07/04 Fuel line #4 thermostat #1a failure•2/24/05 Fuel line #4 thermostat failure; Primary

heater circuit disabled•4/25/13 Fuel line #2 thermostat failure; Redundant

heater circuit disabled

Solar Array•5/14/2002 Circuit #14 Failure•5/16/2005 Circuit # 6 Failure•8/13/2008 Circuit #14 partial recovery•14 circuits remain operating•no impact to ops

•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•09/03/2008 SSR PWA #23 Recovered•10/12/2013 SSR PWA #11 Loss•Each PWA is 4% loss of launch capacity•Boards are likely recoverablePerformance nominal

•05/05/2004 Gyro 3 Shut Off •1-gyro control system in development

≈ 16 years of on-orbit operations

•5/31/2003 SLC Failure•4/01/2007 Bumper mode

Remote Tlm Cmd (RTC) Box•09/27/2014 RTC A Failover

Power Subsystem

Power Control Unit• 10/18/2014 BVR failover

Landsat 7 Spacecraft Status

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Landsat 8 Spacecraft Status

Operational Land Imager

Thermal Infrared Sensor• 10/1/2014 - Side-A SSM Encoder

Propulsion SubsystemThermal Control System

Electrical Power SystemAttitude Control System

RF Communications

Command & Data Handling System

X-band System

S-band System

Batteries

Solid State Recorder

Solar array

≈ 2 years of on-orbit operations

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Operational Land Imager (OLI)

• Pushbroom VIS/SWIR sensor • Four-mirror telescope • Focal Plane Assembly (FPA)• 6916 active detectors per band• Each FPM is 494 detectors wide• Resolution 30 m (15 m pan)• 185 km swath

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4 optical element refracting telescope

Focal plane consists of 3 staggered QWIP arrays (operates at 43 k temp)

Two spectral channels: Band 10: 10.6 μm - 11.2 μm Band 11: 11.5 μm - 12.5 μm

Push-broom configuration: ~1850 detectors across-track per band

185 km ground swath; 100 meter pixel size on ground

For calibration purposes, a Scene Select Mechanism (SSM) switches instrument view between nadir, deep space port, and blackbody

Thermal Infrared Sensor (TIRS)

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Land Imaging User Needs Statistics• Based on NLIR Pilot Project and 2012

USGS RFI

• Spatial resolution• Majority of routine user applications

require 30m for VSWIR, 120m for TIR

• Spectral Coverage• User applications clearly rely heavily on

aggregated band combinations• Very few visible spectra only (or VNIR

only) applications were identified• Simultaneous VSWIR and TIR

measurement provide significantly more value than each measurement individually

• Revisit Rate• User need for increased revisit rates

clearly evident with 70% of applications requiring ≤ 8 day revisit

• Revisit rate of 16 days satisfies less than 40% of user applications

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National Earth Observation Assessment 2012• First National Earth Observation Assessment (EOA 2012)

• http://www.whitehouse.gov/sites/default/files/microsites/ostp/NSTC/national_plan_for_civil_earth_observations_-_july_2014.pdf

• Conducted to inform the National Plan for Civil Earth Observations • Identified a portfolio of observing systems relied upon by the Federal agencies • Provided a cross-cutting and integrated look at observing capabilities (satellite and

non-satellite systems)• Quantified the impact of those observing systems in delivering societal benefit

• The organizing framework for the assessment was 12 Societal Benefit Areas (SBAs) plus Reference Measurements

• Reference Measurements include geodesy, bathymetry, topography, geolocation, etc.

• Agriculture & Forestry, Biodiversity, Climate, Disasters, Ecosystems (Terrestrial & Freshwater), Energy & Mineral Resources, Human Health, Ocean & Coastal Resources & Ecosystems, Space Weather, Transportation, Water Resources, Weather

• SBA Teams each produced an assessment for their SBA

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Landsat – EOA 2012 Results• Assessment of 362 US Earth Obs. Systems

(EOS) (space, air, land, and sea platforms) contributions to 13 Societal Benefit Areas (SBAs)

• Landsat was 3rd out of total, and Landsat 2nd “most critical SBA impact” of 132 satellite systems (GPS=1)

• 10 of 13 (77%) SBAs use Landsat data• Landsat has a Significant Impact on 6

SBAs; • Ranked #1 for contributions in

Biodiversity, Ecosystems, and Energy • Ranked #2 for contributions in

Agriculture/Forestry, Climate, Human Health, and Water

• 31 of 52 (60%) Sub-SBA Areas utilize Landsat• Landsat had a Significant Impact on 15

Sub-SBAs and a Moderate Impact on 6 Sub-SBAs

Societal Benefit Areas (inner ring)

Sub-Societal Benefit Areas (outer ring)

LANDSAT

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Landsat GCP Improvement• L8 geolocation accuracy has identified areas where the GLS-

derived global GCP library is deficient• Triangulation updates are proceeding in three phases

• Phase 1: high priority areas completed September 3, 2014• Phase 2: low latitude areas near completion (54/61 blocks

complete)• GeoScience Australia requested that we rework several areas

that were not on our original problem list to better harmonize the GLS framework with their national imagery database

• Phase 3: high latitude areas not started• The existing control library image chips are all Landsat 7 ETM+

(8-bit) circa 2000• Once the triangulation updates are complete, new 16-bit OLI image

chips will be extracted• The original ETM+ chips will also continue to be used

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GCP Improvement Phase 1 and Phase 2

Phase 1

Phase 2

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Landsat 8 Single-to-Noise

Improved SNR allows the more accurate detection and characterization of subtle land and water conditions. 33

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Landsat 8 Signal-to-Noise

Improved SNR allows the more accurate detection and characterization of subtle land and water conditions and changes.

0

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100

150

200

250

300

350

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CA Blue Green Red NIR SWIR1 SWIR2 Pan Cirrus

ETM OLI

3535Leo Lymburner, Geosciences Australia

Landsat 8’s 12-bit quantization eliminates bright target saturation

Landsat 1-7 signal saturation that affected the ability to detect subtle changes in bright surfaces is no longer an issue. This is improving the detection and mapping of land degradation and the characterization of snow and ice.

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Landsat 8’s cirrus band improves cloud detection

Thermal Cirrus

Thermal Cirrus

Zhe Zhu

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Detection of cirrus clouds using band 9 improves atmospheric correction of Landsat 8 multispectral

data.

Landsat 8 Improved Cloud Detection

Band 9 -Cirrus

Surface Reflectance

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Landsat 8 data are improving land cover classification

Landsat 8 FCC Landsat 7 LC Landsat 8 LC

In classification tests over New Orleans and Boston, Landsat 8 land cover results were 19.5% better than Landsat 7.

Curtis Woodcock, Boston UniversityLandsat 8 Performance Highlights: What have we learned from and about Landsat 8? Tom Loveland USGS EROS Center, 2/11/2014

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Improved Landsat 8 geodetic control allows accurate measurement of ice motion

The high precision of L8 scene geo-location, as well as the improved radiometric fidelity, is enabling accurate measurement of glacial ice motion.

Using pairs of Landsat 8 panchromatic bands, 0.3 pixels (about 5 meters) of ice motion were detected over a 32 day period in the summer of 2013.

M. Fahnestock, pers.comm.

Hubbard Glacier, Alaska P61 R01812 Jul. 2013; 13 Aug. 2013; 32 days sep.

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Analysis by John Schott, RIT, demonstrates that Landsat 8 performance is sufficient to measure chlorophyll, colored dissolved organic material, and suspended materials in near shore areas.

Coast aerosol band and improved radiometry benefits water quality studies

Landsat 8 Performance Highlights: What have we learned from and about Landsat 8? Tom Loveland USGS EROS Center, 2/11/2014

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Bahrain and China Bridge Targets

PontchartrainCauseway Interstate-10

Bridge

West Section

East Section

Center Section

King Fahd Causeway

Qingdao Bridge

Panchromatic Band ImagesSingle Span Bridges

Analysis of MTF with 101 bridge targets

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Landsat 8 Web-Enabled Landsat Data

David Roy, SDSU

Landsat 8 Performance Highlights: What have we learned from and about Landsat 8? Tom Loveland USGS EROS Center, 2/11/2014

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Landsat a “Gold Standard” System• Landsat data has always been well calibrated

and characterized making it a key long term monitoring record

• Usefulness of any remote sensing dataset depends on its traceability to reference standards

• “Gold Standard” is a term that has been coined by many satellite data providers to refer to a system used as a reference standard for their calibration

• Landsat is considered by the community to be the “gold standard” because of its robust calibration strategy

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Landsat Calibration Process• Landsat robust calibration strategy involves:

• Detailed pre-launch characterization• Use of on-board calibration reference lamps and solar diffusers• Use of an operational image assessment and calibration

process• On-going vicarious calibration (field campaigns – instrumented

test sites)• Collection and evaluation of pseudo invariant test sites on a

regular basis to monitor long term stability (key to recalibration of the Landsat archive)

• Use of inter-calibration with other systems• On-going updates and provides calibration information to

users• Accessibility and availability of all data and ancillary

information

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TIRS Scene Select Mirror Anomaly SSM encoder current began

increasing last Summer/Fall Reached yellow limit

December 19, 2014 Encoder powered down Product generation system

couldn’t handle no encoder TIRS imagery zeroed through

early March Software updated April 23, 2015

TIRS electronics switched to side-B March 4, 2015 Radiometric and Geometric

quality attained once more

Typical OLI-TIRS alignment

OLI-TIRS alignment without encoder

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• Worst case measured values for selected TIRS requirements based on on-orbit image data

TIRS On-Orbit Performance Breakdown

*After bias adjustment ** Scene dependent

Note: Worst case radiometric accuracy and uniformity performance occurs in band 11; band 10 approximately a factor of 2 better

Requirement Measured Value Required Value UnitsNEdT (@300K) 0.05 < 0.4 KelvinNEdL 0.008 < 0.059, < 0.049 W/m²/sr/µmSaturation Radiances 28.4, 19.2 20.5, 17.8 W/m²/sr/µm40 min. Radiometric Stability (1σ) 0.1 < 0.7 PercentInoperable Detectors 0 < 0.1 PercentSwath Width 186.2 > 185 KilometersGround Sample Distance 103.424 < 120 MetersBand Registration Accuracy 10.4 < 18 MetersTIRS-to-OLI Registration Accuracy 20.6 < 30 Meters

Band 10 Band 11Absolute Radiometric Accuracy ~ 5 (~ 2*) ~ 10 (~ 5*) < 2 PercentUniformity Field-of-View ~ 1 ** ~ 2 ** < 0.5 PercentUniformity Banding RMS ~ 1 ** ~ 2 ** < 0.5 PercentUniformity Banding St.Dev. ~ 2 ** ~ 4 ** < 0.5 PercentUniformity Streaking < 0.5 < 0.5 < 0.5 Percent

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Sustainable Land ImagingPresident’s 2016 Budget Request

• The budgets of both the USGS and NASA provide funding to extend and build on the Landsat data stream through a Sustainable Land Imaging (SLI) Program

• USGS will be responsible for:• assessing users’ needs• developing the ground systems• operating the on-orbit spacecraft launched by NASA• acquiring auxiliary foreign or commercial data sets• collecting, archiving, processing and distributing the SLI system

data to users

• NASA will have responsibility for developing, launching and checking out land imaging satellite missions

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Sustainable Land Imagingin FY16 President’s Budget

• The 3+1 part program, with the essential investments in technology and observational innovation to ensure a world class, sustainable, and responsible land imaging program through 2035:

• Class D Thermal Infrared Free Flyer (TIR-FF) to launch ASAP (estimated NLT 2019) and to fly in constellation with a reflective band imager• Low cost mitigation against an early loss of the Landsat 8 Class C TIRS, while

demonstrating feasibility of constellation flying

• Landsat 9 (fully Class-B rebuild of Landsat 8) to launch in 2023• Low programmatic risk implementation of a proven system with upgrades to TIRS to

bring the whole system to Class B

• Land Imaging Technology and Systems Innovation (e.g. ACMS, hyperspectral)• Conducts hardware, operations and data management/processing investments to

reduce risk in next generation missions

• Landsat 10, Class B full spectrum, launch in 2030• Mission definition to be informed by the Technology investments in 2015 – 2018,

leading to a key decision point around 2019