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