LANDSAT: Difference between revisions
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* data download from [http://landsat.usgs.gov/ USGS LANDSAT archive] and [http://glcfapp.umiacs.umd.edu GLCF] | * data download from [http://landsat.usgs.gov/ USGS LANDSAT archive] and [http://glcfapp.umiacs.umd.edu GLCF] | ||
== Modules == | |||
* {{cmd|i.landsat.rgb}} - auto-enhance colors | |||
* {{cmd|i atcorr}} - correct top of atmosphere to surface reflectance | |||
* {{cmd|i.oif}} - calculate the 3 bands showing the greatest difference (for use as R,G,B bands) | |||
* {{AddonCmd|i.landsat.toar}} (addon) - top of atmosphere radiance | |||
* {{AddonCmd|i.landsat.acca}} (addon) - cloud removal | |||
* {{AddonCmd|i.landsat.dehaze}} (addon) - haze removal | |||
== Obtaining data == | |||
* [[Global datasets]] | |||
* USGS GloVis Java app: http://glovis.usgs.gov | |||
== LANDSAT Pre-Processing == | == LANDSAT Pre-Processing == | ||
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# Use {{cmd|r.in.gdal}} to import into GRASS GIS. | # Use {{cmd|r.in.gdal}} to import into GRASS GIS. | ||
# In grass/add-ons look for any of these to correct from radiance to reflectance at top of atmosphere | # In grass/add-ons look for any of these to correct from radiance to reflectance at top of atmosphere | ||
## i.landsat.toar | ## {{AddonCmd|i.landsat.toar}} | ||
## i.dn2full.l5 | ## {{AddonCmd|i.dn2full.l5}} | ||
## i.dn2full.l7 | ## {{AddonCmd|i.dn2full.l7}} | ||
# Use {{cmd|i.atcorr}} | # Use {{cmd|i.atcorr}} to correct top of atmosphere to surface reflectance | ||
== Notes == | |||
The {{AddonCmd|i.landsat.toar}} and {{AddonCmd|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 {{cmd|r.reclass}} to rename it without touching the data or wasting disk space: | |||
<source lang="bash"> | |||
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 | |||
</source> | |||
[[Category:Documentation]] | [[Category:Documentation]] | ||
[[Category:FAQ]] | [[Category:FAQ]] | ||
[[Category:Image processing]] | [[Category:Image processing]] | ||
Revision as of 08:36, 9 September 2010
LANDSAT Data Availability
- data download from USGS LANDSAT archive and GLCF
Modules
- i.landsat.rgb - auto-enhance colors
- atcorr.html 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:
- Open GRASS GIS, select create location from georeferenced file
- Use r.in.gdal to import into GRASS GIS.
- In grass/add-ons look for any of these to correct from radiance to reflectance at top of atmosphere
- 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