Filling in the gaps in Landsat 7 data

Filling in the gapsin Landsat 7 data

Northwest GIS Users Group ConferenceBoise, Idaho, October 19 – 21, 2011

William J. KramberIdaho Department of Water Resources

Boise, Idaho

Dr. Richard G. Allen and Dr. Ricardo TrezzaKimberly Research Center, University of Idaho

Kimberly, Idaho

Landsat USGS/NASA mission L5 launched 1984 L7 launched 1999

(damaged May, 2003)

30 meter pixels 16 day cycle 100 by 100 miles Free

Landsat 8 will launch in December 2012

Landsat 9?

NASANASA

Landsat 7

p40r30_l7_20110728.img

Gaps in Landsat 7 Scan line corrector failed on May 31, 2003

Procedures Reproject Landsat 7 image to IDTM83 Produce NDVI Change gaps to unique value Compute mean NDVI of CLU polygons Fill in gaps with mean NDVI

Produce NDVINormalized Difference Vegetation Index ArcInfo tool developed by Eric Rafn Converts Landsat bands 3 and 4 to reflectance Outputs NDVI image

(IR – Red) / (IR + Red) sensitive to vegetation density

NDVI_toa.img

Change gaps to unique value

Compute mean NDVI of CLU polygons

ArcInfo Zonal Statistics (ignore nodata, snap to input)Input Output

Fill in gaps with mean NDVI

Concern about Landsat’s future Landsat 5 is 27 years old Landsat 7 is 12 years old Landsat 8 is scheduled for launch in Dec. of 2012 Funding for Landsat 9 is uncertain

Landsat used in Idahosince 1975

Water rights monitoring Adjudication Land use and land cover mapping Conservation Reserve Enhancement Program Mapping Evapotranspiration

More InformationFilling gapsChen,J., et al., 2011, A simple and effective method for filling gaps in Landsat ETM+ SLC-off images, Remote Sensing of Environment, v.115, no.4, p.1053-1064.

Landsathttp://landsat.gsfc.nasa.gov/about/http://www.idwr.idaho.gov/geographicinfo/landsat/LandsatConcerns.htm

NDVIhttp://earthobservatory.nasa.gov/Features/MeasuringVegetation/measuring_vegetation_1.php

Common Land Unit (CLU)http://www.fsa.usda.gov/FSA/apfoapp?area=home&subject=prod&topic=clu

Landsat mosaic