LANDSAT

LANDSAT Data Availability

• data download from USGS LANDSAT archive and GLCF

Modules

• i.landsat.rgb - auto-enhance colors
• i.atcorr - correct top of atmosphere to surface reflectance
• i.oif - calculate the 3 bands showing the greatest difference (for use as R,G,B bands)
• i.landsat.toar (addon) - top of atmosphere radiance
• i.landsat.acca (addon) - cloud removal
• i.landsat.dehaze (addon) - haze removal

Obtaining data

• Global datasets
• USGS GloVis Java app: http://glovis.usgs.gov

LANDSAT Pre-Processing

Some notes from Yann Chemin:

1. Open GRASS GIS, select create location from georeferenced file
2. Use r.in.gdal to import into GRASS GIS.
3. In grass/add-ons look for any of these to correct from radiance to reflectance at top of atmosphere
   1. i.landsat.toar
   2. i.dn2full.l5
   3. i.dn2full.l7
4. Use i.atcorr to correct top of atmosphere to surface reflectance

Notes

The i.landsat.toar and i.landsat.acca modules want the maps to be named such as "scenename.1, .2, .3", etc. for the different bands. GloVis names like _B10, _B20, _B30, etc.

Here's a little trick with r.reclass to rename it without touching the data or wasting disk space:

BASE=L71074092_09220040924_B

for BAND in 20 30 40 50 61 ; do
  BAND1st=`echo $BAND | sed -e 's/0$//'`
  r.reclass in="$BASE$BAND" out=$BASE.$BAND1st << EOF
    * = *
EOF
done