NAME
dbdec - Decimate waveform data
SYNOPSIS
dbdec
[-sift sift_expr]
[-c calper]
[-wfdir wfdir]
[-f format]
dbin
dbout
chan_maps
dec_stage1
[dec_stage2
...]
SUPPORT
Contributed code: NO BRTT support.
THIS PIECE OF SOFTWARE WAS CONTRIBUTED BY THE ANTELOPE USER COMMUNITY. BRTT DISCLAIMS ALL OWNERSHIP, LIABILITY, AND SUPPORT FOR THIS PIECE OF SOFTWARE.
FOR HELP WITH THIS PIECE OF SOFTWARE, PLEASE CONTACT THE CONTRIBUTING AUTHOR.
DESCRIPTION
dbdec
will decimate waveform data.
This program will only work with v. 3.0 of the CSS schema.
COMMAND LINE ARGUMENTS
-
-sift sift_expr
A sifting expression to be applied to the input wfdisc table
for determining which waveform segments to process.
This should be formed as a normal expression, such as 'sta == "AAK"'
to get just the waveform segments for station AAK. Note that the channel mappings
also effectively sift the data.
This argument is optional and if it is ommitted, then all waveforms are processed
subject to the channel mappings.
-
-c calper
If this argument is specified, then the calib and calper values in
the output wfdisc table will be recomputed according to the specified
calper value. In addition the instrument response files will be modified
to reflect the new normalization value.
This argument is optional and if it is ommitted, then the calib, calper
and instrument response normalizations remain unchanged. Note that the decimation
FIR stages are always included to produce new instrument response files
for the decimated waveforms.
-
-wfdir wfdir
The wfdir argument specifies where the output waveform files are
to be stored. The dir entry in the output wfdisc table is
generated by concatenating the wfdir argument with the dir
entry from the input wfdisc table. If the wfdir specification
is of the form :stringi:stringo:, then a string substitution
is attempted on the dir entry from the input wfdisc table
to form the dir entry in the output wfdisc table.
This argument is optional and if it is ommitted, then the output decimated
waveform file directory tree will be the same as the input tree. Note that
in this case, in order to avoid file collisions,
the dir path in the input wfdisc tables must be
relative (not absolute) and the output database wfdisc file must be
in a different directory than the input wfdisc file.
-
-f format
The format for the decimated waveform data. This should be a normal
datatype value, such as s2, s4, t4, etc.
This argument is optional and if it is ommited, then the output format
is the same as the input format.
-
dbin
The name of the input database.
This argument is required.
-
dbout
The name of the output database.
This argument is required.
-
chan_maps
A list of channel code mappings. This is a comma separated list of the form
outchan1=inchan1,outchan2=inchan2,... with no embedded
white space that describes how input channel codes are mapped to output
channel codes. Only the input channels in this list will be processed.
If the output channel code is the same as the input channel code, then
the output database, dbout, must be different from the input
database, dbin. An example of this argument is
SHN=EHN,SHE=EHE,SHZ=EHZ
This argument is required.
-
dec_stage [dec_stage2 ...]
A set of decimation stage response files. This list of file names refers
to one or more decimation stages that are to be applied to the data.
Each response stage file is assumed to contain the coefficients for
a normalized FIR filter in CSS response file format.
At least one stage must be specified.
SEE ALSO
dbex_eval(3)
BUGS AND CAVEATS
Will now read miniseed (sd) input data but output will be t4.
Should make output format always a clone of input, which is the
behaviour for other formats.
Antelope User Group Contributed Software