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NAME
i.in.spotvgt - Import of SPOT VGT NDVI file into a raster map
KEYWORDS
raster, imagery, import
SYNOPSIS
i.in.spotvgt
i.in.spotvgt help
i.in.spotvgt [-a] file=string [rast=string] [--overwrite] [--verbose] [--quiet]
Flags:
- -a
- Also import quality map (SM status map layer) and filter NDVI map
- --overwrite
- Allow output files to overwrite existing files
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- file=string
- existing SPOT VGT NDVI HDF file (0001_NDV.HDF)
- rast=string
- Name for output raster map
DESCRIPTION
i.in.spotvgt imports SPOT Vegetation (1km, global) NDVI data sets.
After import the digital numbers (DN) are remapped to VEGETATION NDVI
values and the NDVI color table is applied. The imported DN map is
removed after remapping.
Apparently missing raster cells due to bad pixel quality are reconstructed
by the SPOT operating team in the NDVI file. The differences between the
filtered (-a flag) and raw NDVI map should be compared.
NOTES
The SPOT VGT files are delivered in HDF4 (Hierarchical Data Format Release 4)
format. It is required to have the GDAL libraries installed with HDF4 support.
Export of entire world SPOT VGT maps
When working with SPOT VGT with entire world extent, it is recommended
to zoom to w=180W and e=180E instead of using the map
extent for map export. These entire world SPOT VGT data are exceeding
-180.0 degree which can lead to unhelpful large East-West coordinates in
the exported file. It is also recommended to then use an export command
which respects the user settings. Example:
# import:
i.in.spotvgt 0001_NDV.HDF
# export:
g.region w=180W e=180E n=75:00:16.071429N s=56:00:16.069919S res=0:00:32.142857 -p
r.out.gdal 0001_NDV format=GTiff out=spotndvi.tif
SEE ALSO
r.in.gdal,
r.out.gdal
REFERENCES
SPOT Vegetation (1km, global) NDVI data set server
SPOT Vegetation FAQ
SPOT Vegetation Status Map (SM) - Quality map
AUTHOR
Markus Neteler
Last changed: $Date: 2011-11-08 01:42:51 -0800 (Tue, 08 Nov 2011) $
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