NAME

       i.in.spotvgt  - Imports SPOT VGT NDVI data into a raster map.

KEYWORDS

       imagery, import, NDVI, SPOT

SYNOPSIS

       i.in.spotvgt
       i.in.spotvgt --help
       i.in.spotvgt [-a] input=name  [output=name]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -a
           Also import quality map (SM status map layer) and filter NDVI map

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       input=name [required]
           Name of input SPOT VGT NDVI HDF file

       output=name
           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.

EXAMPLE

   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
       1.13 How must I read the 8 bits of the status map? - Quality map

AUTHOR

       Markus Neteler

SOURCE CODE

       Available at: i.in.spotvgt source code (history)

       Accessed: Friday Apr 04 01:21:11 2025

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       © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual

GRASS 8.4.1                                                                                 i.in.spotvgt(1grass)