NSLRSDA Science TeamNSLRSDA Science Team
Samuel N. GowardSamuel N. GowardACC IIIACC III
19 April 2006 19 April 2006
30 years of Landsat –Data Cubes30 years of Landsat –Data Cubes1972 1974 1976 1978 1980
200420022000199819961994
199219901984 19881986
Year Disturbed
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
Forest
Nonforest
Disturbance and RegrowthDisturbance and Regrowth
Lake Anna, VA, 60 km NW of Richmond, VA
Major disturbance
0
5
10
15
20
25
1985 1990 1995 2000
Year
FI
Minor disturbance
0
5
10
15
20
25
1985 1990 1995 2000
Year
FI
% disturbance
0% 100%
LEDAPS
Masek LEDAPS North American Decadal Disturbance
Archived Data IssuesArchived Data Issues
Transcript problemsTranscript problems Technical problemsTechnical problems Observation problemsObservation problems
• RadiometryRadiometry
• GeometryGeometry
• Seasonality and Cloud CoverSeasonality and Cloud Cover
RadiometryRadiometry
Dropped/Bad ScansDropped/Bad ScansData from US Forest Service ArchiveData from US Forest Service Archive
Dropped scans observed Dropped scans observed in L5 TM scene in L5 TM scene processed by EOSAT processed by EOSAT (transcription error?)(transcription error?)
No dropped scans were No dropped scans were observed when the same observed when the same scene was ordered at scene was ordered at EROS and transcribed EROS and transcribed through TMACSthrough TMACS
TMACS Bands 3,2,1EOSAT Bands 3,2,1
TM_12July1997_P17R31 (5017031009719310 )
Some might be fixable!
USFS Data EROS Reprocessed
MSS Wide Band Video (WBV) image MSS Wide Band Video (WBV) image RadiometryRadiometry??
Both Landsat-1 MSS images, acquired on 1974/10/10
WRS1 p16/r 33
WRS1 p16/r 34
From WRS1 p16/r 33
From WRS1 p16/r 34
ABNORMAL –WBV EFFECT
MSS Image Striping/BandingMSS Image Striping/Banding
Browse image does not show
stripe
Scene ID: LM1016033007425690Browse image in GloVis
Overview
Full resolution
Processed image has extensive stripes.
TM_27Aug1984
*All 4,3,2 Gaussian Enhanced*
ETM_02Aug2001 TM_29May1986TM_12Aug1990TM_11July1996TM_05Aug1999
TM/ETM+ BandingTM/ETM+ Banding
Geo-Geo-RegistrationRegistration
MSS Wide Band Video (WBV) imagesMSS Wide Band Video (WBV) images
WRS1 18/31
1974-05-30 1972-08-20
ABNORMAL –WBV EFFECT
WRS1 16/33
1974-09-13 1974-10-10
1972/10/11
1981/09/211997/07/14 1992/10/20
1975/10/141978/10/25
WRS2 path 15/row 34, East of Richmond, VAWRS2 path 15/row 34, East of Richmond, VA
Richmond AirportRichmond Airport
MSS ImagesMSS Images Geo-location errors -10s of kmsGeo-location errors -10s of kms
WRS2 path 15/row 34, East of Richmond, VAWRS2 path 15/row 34, East of Richmond, VA
2000/10/10 1996/10/151997/07/14
1992/10/201993/10/231994/08/23
TM imagesTM images Geo-location errors up to 400 mGeo-location errors up to 400 m
Need for terrain correction – theoretical analysis of Need for terrain correction – theoretical analysis of terrain height incurred geolocation errorterrain height incurred geolocation error
D0
D
A
H
A – platform altitude (705 km)
D – actual pixel location (from the nadir view pixel)
D0 – calculated pixel location without terrain correction (from the nadir view pixel)
H – terrain height
E – geolocation error
D0 / A = D / (A - H)
D = D0 – D0 x H / A
E = D0 – D
= D0 x H / A
Assumption: Earth surface is flat within a TM scene, which is reasonable because the maximum view angle is 7.5 degree.
Assumed terrain
Actual terrain
SeasonalitySeasonalityand Cloudsand Clouds
“Seasonality” includes variable…•Solar geometry (BRDF)•Canopy structure (leaf area, understory, etc)•Leaf pigments
Example: GeoCover p18/r26, N. Georgia(RGB = 321 composite)
TM, Jun 6, 1993
ETM+, Oct 25, 2000
SeasonalitySeasonalitySolutions…
Acquire anniversary date imagesApply BRDF corrections
Seasonality and Cloud Seasonality and Cloud Contamination Contamination
(L7 16-Day Temporal Repeat – Washington DC region, 2000)(L7 16-Day Temporal Repeat – Washington DC region, 2000)May 11 May 27 June 12
June 28
July 14 July 30
Data SourcesData SourcesPrimary ArchivesPrimary Archives USGS EROS USGS EROS
EOSATEOSAT International Ground StationsInternational Ground Stations
Secondary ArchivesSecondary Archives U.S. Forest ServiceU.S. Forest Service UMd Global Land Cover UMd Global Land Cover
FacilityFacility Earthsat GeocoverEarthsat Geocover Multi-Resolution Land CoverMulti-Resolution Land Cover USDA (?)USDA (?)
SourceSource Geometric RegistrationGeometric Registration RadiometricRadiometricCalibrationCalibration
Resampling MethodResampling Method
USGS EROSUSGS EROS Systematic Systematic PrecisionPrecisionTerrain (ortho)Terrain (ortho)
Pre-flightPre-flightPeriodic VicariousPeriodic VicariousPeriodic LampsPeriodic LampsScene LampsScene Lamps
Nearest neighborNearest neighborBilinearBilinearCubic convolutionCubic convolutionMTF (GeoCover2K)MTF (GeoCover2K)
EOSATEOSAT TBDTBD Pre-FlightPre-Flight TBDTBD
International Ground International Ground StationsStations
UnknownUnknown, likely vary from , likely vary from IGS to IGSIGS to IGS
UnknownUnknown, likely vary , likely vary from IGS to IGSfrom IGS to IGS
Nearest neighborNearest neighbor BilinearBilinear Cubic convolutionCubic convolution
Data ProcessingData Processing
NSLRSDA Science TeamNSLRSDA Science Team
Many sources of data errors and Many sources of data errors and variationsvariations
Various sensors and operatorsVarious sensors and operators Many possible (and inconsistent) Many possible (and inconsistent)
solutionssolutions Complex Sorting Process that Need Complex Sorting Process that Need
Technical and Scientific GuidanceTechnical and Scientific Guidance