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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