Provided by: grass-doc_6.4.3-3_all bug

NAME  - Import of SPOT VGT NDVI file into a raster map


       raster, imagery, import

SYNOPSIS help [-a] file=string  [rast=string]   [--overwrite]  [--verbose]  [--quiet]

           Also import quality map (SM status map layer) and filter NDVI map

           Allow output files to overwrite existing files

           Verbose module output

           Quiet module output

           existing SPOT VGT NDVI HDF file (0001_NDV.HDF)

           Name for output raster map

DESCRIPTION  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.


       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: 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.out.gdal


       SPOT Vegetation (1km, global) NDVI data set server
       SPOT Vegetation FAQ
       SPOT Vegetation Status Map (SM) - Quality map


       Markus Neteler

       Last changed: $Date: 2011-11-08 01:42:51 -0800 (Tue, 08 Nov 2011) $

       Full index

       © 2003-2013 GRASS Development Team