t.rast.patch - GRASS GIS manual

NAME

t.rast.patch - Patches multiple space time raster maps into a single raster map using r.patch.

KEYWORDS

temporal, aggregation, series, raster, merge, patching, time

SYNOPSIS

t.rast.patch

t.rast.patch --help

t.rast.patch [-tzsv] input=name [where=sql_query] output=name [sort=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-t: Do not assign the space time raster dataset start and end time to the output map
-z: Use zero (0) for transparency instead of NULL
-s: Do not create color and category files
-v: Patch to virtual raster map (r.buildvrt)
--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
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'
output=name [required]: Name for output raster map
sort=string: Sort order (see sort parameter); Options: asc, desc; Default: desc

DESCRIPTION
EXAMPLE
SEE ALSO
AUTHOR

DESCRIPTION

This module patches raster maps that have gaps in time with subsequent maps (within a space time raster dataset) using r.patch or r.buildvrt. Hence it is a wrapper for those two modules in the temporal domain.

By default r.patch is used to create a patched raster map. Especially for temporary data, using r.buildvrt for patching can be advantageous with regards to processing time and storage space. r.buildvrt creates a virtual raser map and is used when the v-flag is given. The v-flag excludes the z-flag (using zero (0) for transperancy) and s-flag (do not create color and category files).

The input of this module is a single space time raster dataset, the output is a single raster map layer. A subset of the input space time raster dataset can be selected using the where option. The sorting of the raster map layer can be set using the sort option. Be aware that the sorting of the maps significantly influences the result of the patch. By default the maps are sorted by desc by the start_time so that the newest raster map is the first input map in r.patch/r.buildvrt.

Please note that the color table of the first input raster is used for the resulting map when the v-flag is used. Values in the resulting raster map that exeed the range of that first raster map will then be rendered on the screen like no data. In that case, please update the color table or the resulting map with r.colors

t.rast.patch is a simple wrapper for the raster module r.patch or r.buildvrt.

EXAMPLE

The example uses the North Carolina extra time series of MODIS Land Surface Temperature maps (download). (The mapset has to be unzip in one of the North Carolina locations.)

Patching the MODIS Land Surface Temperature for 2016 (filling missing pixels by subsequent maps in the time series):

t.rast.patch input=LST_Day_monthly@modis_lst output=LST_Day_patched_2016 \
  where="start_time >= '2016-01' and start_time <= '2016-12'"
r.info LST_Day_patched_2016

Patching the MODIS Land Surface Temperature for 2016 (filling missing pixels by subsequent maps in the time series) using a virtual mosaic (r.buildvrt):

t.rast.patch -v input=LST_Day_monthly@modis_lst output=LST_Day_patched_2016_vrt \
  where="start_time >= '2016-01' and start_time <= '2016-12'"
# Assign a new color table that covers the entire range of the resulting map
r.colors map=LST_Day_patched_2016_vrt color=grey
r.info LST_Day_patched_2016_vrt

AUTHOR

Anika Bettge, mundialis GmbH & Co. KG

SOURCE CODE

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

Latest change: Sunday Oct 02 16:35:26 2022 in commit: e2df8ecc671aa3d1892fae2edbdd5e6e86078763