• Antelope Release 5.5 Linux 2.6.32-220.el6.x86_64 2015-04-21

 

NAME

dbtc, correctdt - perform waveform and database time corrections

SYNOPSIS


dbtc [-p parfile] [-t stime] [-v]
                gdb:gnet:gsta:gch
                bdb:bnet:bsta:bch

correctdt [-v] [-m srcmatch] [-t stime] bdb

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

Seismic networks can have clock problems and as a result produce data with incorrect time. dbtc finds time corrections for seismic data for network (bad data) by cross correlating with data from a co-located station from another network that does not have a timing problem (good data), writing a tcorrection table.

correctdt reads this tcorrection table and fixes times in the wfdisc and arrival tables. When the data is in mini-seed format, the times in the SEED headers are also corrected.

dbtc

dbtc needs references to both data with bad timing, and the data with good timing. The (bad data) segment must be specified in the form of bdb:bnet:bsta:bch, where
bdb database name of data with a bad time
bnet network name of data with a bad time
bsta station name of data with a bad time
bch channel name of data with a bad time
Similarly, the (good data) must be specified in form of gdb:gnet:gsta:gch, where
gdb db name of data with a good time
gnet network name of data with a good time
gsta station name of data with a good time
gch channel name of data with a good time

dbtc makes a tcorrection table with name bdb.tcorrection and with the following fields:


   time  tcor gnet gsta gchan gsamprate
              bnet bsta bchan bsamprate lddate

tcor is the correction factor which needs to be added to the bad data at time time.

If bad data and good data have different sampling rates dbtc does a re-sampling of bad data and then runs the cross-correlation.

correctdt

For each value of time in the wfdisc and arrival, correctdt looks up the tcor value for the closest prior time in the tcorrection table and applies the tcor value as a static correction. There is no provision at this time for linear interpolation for applying time corrections.

OPTIONS

dbtc

correctdt

PARAMETER FILE

dbtc uses a parameter file, which has the following parameters:

EXAMPLE

Find time correction for anza network. Bad data is data/anza:AZ:PFO:BHZ and good data is nrdc/ida:II:PFO:shz


% dbtc nrdc/ida:II:PFO:shz data/anza:AZ:PFO:BHZ

% correctdt data/anza

AUTHOR

Marina Glushko
Antelope User Group Contributed Software
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