t.rast.ndvi - GRASS manual

NAME

t.rast.ndvi - Calculates NDVI from a given STRDS.

KEYWORDS

SYNOPSIS

t.rast.ndvi

t.rast.ndvi --help

t.rast.ndvi [-ns] input=name [method=name[,name,...]] output=name basename=basename [red=string] [nir=string] [target=string] [nprocs=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-n: Register Null maps
-s: Check the spatial topology of temporally related maps and process only spatially related maps
--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
method=name[,name,...]: The method to be used for sampling the input dataset; Options: start, during, overlap, contain, equal, follows, precedes; Default: equal
output=name [required]: Name of the output space time raster dataset
basename=basename [required]: Basename for output raster maps; A numerical suffix separated by an underscore will be attached to create a unique identifier
red=string: Bandname to be used as red band; Default: red
nir=string: Bandname to be used as nir band; Default: nir
target=string: Output bandname
nprocs=integer: Number of r.mapcalc processes to run in parallel; Default: 1

DESCRIPTION
SEE ALSO
AUTHOR

DESCRIPTION

t.rast.ndvi calculates NDVI from a STRDS. It uses a single STRDS as input and calculates a new STRDS using the red and nir bands included in the input STRDS.

This module is a front-end for t.rast.mapcalc.

Different bands must be referenced in the expression by data[index] with index being a number starting with 0. For example, with Sentinel-2, data[3] refers to the fourth Sentinel-2 band "S2_4 Visible (Red)". t.rast.bandcalc replaces data[index] with the according selections of the input STRDS.

This module expects several parameters. The resulting space time raster dataset must be specified in the output option together with the basename of generated raster maps that are registered in the resulting STRDS. Empty maps resulting from map-calculation are not registered by default. This behavior can be changed with the -n flag. The flag -s can be used to assure that only spatially related maps in the STRDS's are processed. Spatially related means that temporaly related maps overlap in their spatial extent.

AUTHOR

Markus Metz, mundialis, Germany

SOURCE CODE

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

Accessed: Monday Jul 27 12:30:26 2026