## NAME

t.rast.export - Exports space time raster dataset.

## KEYWORDS

temporal, export, raster, time

## SYNOPSIS

t.rast.export
t.rast.export --help
t.rast.export input=name output=name [directory=name] [compression=string] [format=string] [type=string] [createopt=string[,string,...]] [metaopt=string[,string,...]] [nodata=float] [where=sql_query] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

### Flags:

--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 the input space time raster dataset
output=name [required]
  Name of a space time raster dataset archive
directory=name
  Path to the directory where output is written
  If not given, the default is the current working directory
  Default: ./
compression=string
  Compression method of the tar archive
  Options: no, gzip, bzip2
  Default: bzip2
format=string
  The export format of a single raster map
  Supported are GTiff, AAIGrid via r.out.gdal and the GRASS package format of r.pack
  Options: GTiff, AAIGrid, pack
  Default: GTiff
type=string
  Data type
  Supported only for GTiff
  Options: Byte, Int16, UInt16, Int32, UInt32, Float32, Float64, CInt16, CInt32, CFloat32, CFloat64
createopt=string[,string,...]
  Creation option(s) to pass to the output format driver
  In the form of "NAME=VALUE", separate multiple entries with a comma
metaopt=string[,string,...]
  Metadata key(s) and value(s) to include
  In the form of "META-TAG=VALUE", separate multiple entries with a comma. Not supported by all output format drivers.
nodata=float
  Assign a specified nodata value to output bands
  If given, the nodata value is always written to metadata even if there are no NULL cells in the input band (enhances output compatibility).
where=sql_query
  WHERE conditions of SQL statement without 'where' keyword used in the temporal GIS framework
  Example: start_time > '2001-01-01 12:30:00'

## DESCRIPTION

t.rast.export exports a space time raster dataset (strds) as a tar archive. The archive contains the raster maps either as GeoTIFF files or as GRASS binary files exported using r.pack. The map specific color tables are exported in case of GeoTIFF files. In addition several metadata files are created in the archive that describe the temporal layout. All time stamps are stored in the file "list.txt", for each map one row. The name of the map, the start time and the end time are written. In case of a time instance, the start time is equal to the end time. The "init.txt" file stores the temporal type, the number of maps, the chosen export format and some other metadata. The "proj.txt" file stores the coordinate reference system information as a proj4 string of the project the space time raster dataset was exported from. The file "readme.txt" describes the file format. The output of r.info for each raster map in the space time dataset is stored in "metadata.txt".

The tar archive can be compressed using the compress option. Gzip and bzip2 (default) are available. A where option can be specified, to export only a subset of the space time dataset. Archives exported with t.rast.export can be imported with t.rast.import.

## NOTES

The name of output file has to carry the suffix of the archive type, the following suffix can be used:

- .tar in the case of compress=no
- .tar.bzip2 in the case of compress=bzip2
- .tar.gzip in the case of compress=gzip

## EXAMPLE

In this example, all the raster maps of 2012 of "tempmean_monthly" will be exported:

    t.rast.export input=tempmean_monthly output=tempmean_monthly.tar.bzip2 \
                  where="start_time >= '2012-01-01' and start_time < '2013-01-01'"

    tar xvjf precipitation_daily.tar.bzip2

    2012_01_tempmean.tif
    2012_01_tempmean.color
    2012_02_tempmean.tif
    2012_02_tempmean.color
    2012_03_tempmean.tif
    2012_03_tempmean.color
    2012_04_tempmean.tif
    2012_04_tempmean.color
    2012_05_tempmean.tif
    2012_05_tempmean.color
    2012_06_tempmean.tif
    2012_06_tempmean.color
    2012_07_tempmean.tif
    2012_07_tempmean.color
    2012_08_tempmean.tif
    2012_08_tempmean.color
    2012_09_tempmean.tif
    2012_09_tempmean.color
    2012_10_tempmean.tif
    2012_10_tempmean.color
    2012_11_tempmean.tif
    2012_11_tempmean.color
    2012_12_tempmean.tif
    2012_12_tempmean.color
    list.txt
    proj.txt
    init.txt
    readme.txt
    metadata.txt

    cat init.txt
    stds_type=strds
    format=GTiff
    temporal_type=absolute
    semantic_type=mean
    number_of_maps=48
    north=320000.0
    south=10000.0
    east=935000.0
    west=120000.0

    cat proj.txt
    +proj=lcc
    +lat_1=36.16666666666666
    +lat_2=34.33333333333334
    +lat_0=33.75
    +lon_0=-79
    +x_0=609601.22
    +y_0=0
    +no_defs
    +a=6378137
    +rf=298.257222101
    +towgs84=0.000,0.000,0.000
    +to_meter=1

    cat list.txt
    2012_01_tempmean|2012-01-01 00:00:00|2012-02-01 00:00:00
    2012_02_tempmean|2012-02-01 00:00:00|2012-03-01 00:00:00
    2012_03_tempmean|2012-03-01 00:00:00|2012-04-01 00:00:00
    2012_04_tempmean|2012-04-01 00:00:00|2012-05-01 00:00:00
    2012_05_tempmean|2012-05-01 00:00:00|2012-06-01 00:00:00
    2012_06_tempmean|2012-06-01 00:00:00|2012-07-01 00:00:00
    2012_07_tempmean|2012-07-01 00:00:00|2012-08-01 00:00:00
    2012_08_tempmean|2012-08-01 00:00:00|2012-09-01 00:00:00
    2012_09_tempmean|2012-09-01 00:00:00|2012-10-01 00:00:00
    2012_10_tempmean|2012-10-01 00:00:00|2012-11-01 00:00:00
    2012_11_tempmean|2012-11-01 00:00:00|2012-12-01 00:00:00
    2012_12_tempmean|2012-12-01 00:00:00|2013-01-01 00:00:00

    cat readme.txt
    This space time raster dataset was exported with t.rast.export of GRASS GIS 7

    Files:
           *.tif  -- GeoTIFF raster files
         *.color  -- GRASS GIS raster color rules
         proj.txt -- Projection information in PROJ format
         init.txt -- GRASS GIS space time raster dataset information
         list.txt -- Time series file, lists all maps by name with interval
                     time stamps in ISO-Format. Field separator is |
     metadata.txt -- The output of t.info
       readme.txt -- This file

## SEE ALSO

t.rast.import, t.create, t.info, r.out.gdal, r.pack, t.vect.export

## AUTHOR

Sören Gebbert, Thünen Institute of Climate-Smart Agriculture

## SOURCE CODE

Available at: t.rast.export source code (history)

Accessed: Friday Apr 04 01:21:15 2025

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