.TH t.rast.accdetect 1grass "" "GRASS 8.3.1" "GRASS GIS User's Manual"
.SH NAME
\fI\fBt.rast.accdetect\fR\fR  \- Detects accumulation patterns in temporally accumulated space time raster datasets created by t.rast.accumulate.
.SH KEYWORDS
temporal, accumulation, raster, time
.SH SYNOPSIS
\fBt.rast.accdetect\fR
.br
\fBt.rast.accdetect \-\-help\fR
.br
\fBt.rast.accdetect\fR [\-\fBnr\fR] \fBinput\fR=\fIname\fR  [\fBminimum\fR=\fIname\fR]   [\fBmaximum\fR=\fIname\fR]  \fBoccurrence\fR=\fIname\fR  [\fBindicator\fR=\fIname\fR]  \fBstart\fR=\fIstring\fR  [\fBstop\fR=\fIstring\fR]  \fBcycle\fR=\fIstring\fR  [\fBoffset\fR=\fIstring\fR]  \fBbasename\fR=\fIstring\fR  [\fBsuffix\fR=\fIstring\fR]   [\fBrange\fR=\fImin,max\fR]   [\fBstaend\fR=\fIstart,intermediate,end\fR]   [\-\-\fBoverwrite\fR]  [\-\-\fBhelp\fR]  [\-\-\fBverbose\fR]  [\-\-\fBquiet\fR]  [\-\-\fBui\fR]
.SS Flags:
.IP "\fB\-n\fR" 4m
.br
Register empty maps in the output space time raster dataset, otherwise they will be deleted
.IP "\fB\-r\fR" 4m
.br
Reverse time direction in cyclic accumulation
.IP "\fB\-\-overwrite\fR" 4m
.br
Allow output files to overwrite existing files
.IP "\fB\-\-help\fR" 4m
.br
Print usage summary
.IP "\fB\-\-verbose\fR" 4m
.br
Verbose module output
.IP "\fB\-\-quiet\fR" 4m
.br
Quiet module output
.IP "\fB\-\-ui\fR" 4m
.br
Force launching GUI dialog
.SS Parameters:
.IP "\fBinput\fR=\fIname\fR \fB[required]\fR" 4m
.br
Name of the input space time raster dataset
.IP "\fBminimum\fR=\fIname\fR" 4m
.br
Input space time raster dataset that specifies the minimum values to detect the accumulation pattern
.IP "\fBmaximum\fR=\fIname\fR" 4m
.br
Input space time raster dataset that specifies the maximum values to detect the accumulation pattern
.IP "\fBoccurrence\fR=\fIname\fR \fB[required]\fR" 4m
.br
The output space time raster dataset that stores the occurrence of the the accumulation pattern using the provided data range
.IP "\fBindicator\fR=\fIname\fR" 4m
.br
The output space time raster dataset that stores the indication of the start, intermediate and end of the specified data range
.IP "\fBstart\fR=\fIstring\fR \fB[required]\fR" 4m
.br
The temporal starting point to begin the accumulation, eg \(cq2001\-01\-01\(cq
.IP "\fBstop\fR=\fIstring\fR" 4m
.br
The temporal date to stop the accumulation, eg \(cq2009\-01\-01\(cq
.IP "\fBcycle\fR=\fIstring\fR \fB[required]\fR" 4m
.br
The temporal cycle to restart the accumulation, eg \(cq12 months\(cq
.IP "\fBoffset\fR=\fIstring\fR" 4m
.br
The temporal offset to the begin of the next cycle, eg \(cq6 months\(cq
.IP "\fBbasename\fR=\fIstring\fR \fB[required]\fR" 4m
.br
Basename of the new generated output maps
.br
A numerical suffix separated by an underscore will be attached to create a unique identifier
.IP "\fBsuffix\fR=\fIstring\fR" 4m
.br
Suffix to add at basename: set \(cqgran\(cq for granularity, \(cqtime\(cq for the full time format, \(cqcount\(cq for numerical suffix with a specific number of digits (default %05)
.br
Default: \fIgran\fR
.IP "\fBrange\fR=\fImin,max\fR" 4m
.br
The minimum and maximum value of the occurrence of accumulated values, these values will be used if the min/max space time raster datasets are not specified
.IP "\fBstaend\fR=\fIstart,intermediate,end\fR" 4m
.br
The user defined values that indicate start, intermediate and end status in the indicator output space time raster dataset
.br
Default: \fI1,2,3\fR
.SH DESCRIPTION
\fBt.rast.accdetect\fR is designed to detect accumulation pattern in
temporally accumulated space time raster datasets created by
t.rast.accumulate.
This module\(cqs input is a space time raster dataset resulting from
a t.rast.accumulate run.
.PP
The \fBstart\fR time and the \fBend\fR time of the pattern detection
process must be set, eg. \fBstart=\(dq2000\-03\-01\(dq end=\(dq2011\-01\-01\(dq\fR.
The \fBstart\fR and \fBend\fR time do not need to be the same as for
the accumulation run that produced the input space time raster dataset.
In addition a \fBcycle\fR, eg. \(dq8 months\(dq, can be specified, that
defines after which time interval the accumulation pattern detection
process restarts. The \fBoffset\fR option specifies the time that
should be skipped between two cycles, eg. \(dq4 months\(dq. The \fBcycle\fR
and \fBoffset\fR options must be exactly the same that were used in the
accumulation process that generated the input space time raster dataset,
otherwise the accumulation pattern detection will produce wrong
results.
.PP
The \fBminimum\fR and \fBmaximum\fR values for the pattern detection
process can be set either by using space time raster datasets or
by using fixed values for all raster cells and time steps.
.PP
Using space time raster datasets allows specifying minimum and maximum
values for each raster cell and each time step. For example, we want to
detect the germination (minimum value) and harvesting (maximum value)
dates for different crops in Germany using the growing\-degree\-day (GDD)
method for several years. Different crops may grow in different raster
cells and change with time because of crop rotation. Hence we need to
specify different GDD germination/harvesting (minimum/maximum) values
for different raster cells and different years.
.PP
The raster maps that specify the minimum and maximum values of the
actual granule will be detected using the following temporal relations:
equals, during, overlaps, overlapped and contains. First, all maps with
time stamps \fIequal\fR to the current granule of the input STRDS will be
detected, the first minimum map and the first maximum map that are
found will be used as range definitions. If no equal maps are found, then
maps with a temporal \fIduring\fR relation will be detected, then maps
that temporally \fIoverlap\fR the actual granules and finally, maps that
have a temporal \fIcontain\fR relation will be detected. If no maps are
found or minimum/maximum STRDS are not set, then the \fBrange\fR option
is used, eg. \fBrange=480,730\fR.
.PP
The \fBbase\fR name of of the generated maps must always be set.
.PP
This module produces two output space time raster datasets: occurrence
and indicator. The \fBoccurrence\fR output STRDS stores the time in
days from the beginning of a given cycle for each raster cell and time
step that has a value within the minimum and maximum definition. These
values can be used to compute the duration of the recognized accumulation
pattern.
The \fBindicator\fR output STRDS uses three integer values to mark
raster cells as beginning, intermediate state or end of an accumulation
pattern. By default, the module uses 1 to indicate the start, 2 for
the intermediate state and 3 to mark the end of the accumulation pattern
in a cycle. These default values can be changed using the \fBstaend\fR
option.
.SH EXAMPLE
Please have a look at the t.rast.accumulate example.
.SH SEE ALSO
\fI
t.rast.accumulate,
t.rast.aggregate,
t.rast.mapcalc,
t.info,
r.series.accumulate,
g.region
\fR
.SH AUTHOR
Sören Gebbert, Thünen Institute of Climate\-Smart Agriculture
.SH SOURCE CODE
.PP
Available at:
t.rast.accdetect source code
(history)
.PP
Accessed: Sunday Dec 17 17:22:52 2023
.PP
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.PP
© 2003\-2023
GRASS Development Team,
GRASS GIS 8.3.1 Reference Manual