readme.cvt2segd

su 的源代码库

cvt2segd - Convert SeisNet field record files to SEG-D
Stewart A. Levin, Landmark Graphics 2/18/2004


Seisnet is a PC-based packaged developed by Curtis B. Abshier of
Software Science, Inc. (SSI) which extracts records directly off
a seismic recording system bus for purposes of preliminary processing
and QC.  Each record is stored in a data file with a name patterned like
that in FFID_101%843066991.SEIS, which is included so you will have
an example of the data object format.  The naming of SeisNet data files
adhere to a special format consisting of three fields.  The first field
specifies the type of data stored in the file.  For the data file included
here, the FFID means that the data stored in the file is a "shot record".
An underscore "_" is a separator that separates the first and second fields.  
The second field is the FFID for the shot record.  The "%" sign separates 
the second and third fields.  The third field is a time stamp that is the 
number of seconds from January 1, 1970 when the data were acquired.  We use
this special naming convention to make sorting easy.  The file does not
have to be opened in order to sort on either date or time.

The shot record supplied has:
        Total Number of Traces (Data + Aux): 486
        Number of Data Traces: 480
        Number of Aux Traces: 6
        Sampling Interval: 0.002 seconds.
        Trace Length: 6.144 seconds
        Number of Samples in each trace: 3072
        Sequential Trace Numbers of the AUX traces: 1-6
        Sequential Trace Number of the Data traces: 7-486

cvt2segd is a utility program that accepts a list of such filenames and
extracts the original SEG-D records squirreled away in that format and
concatenates them into one SEG-D dataset, either explicitly named via
the "-o filename" flag or to stdout if no output filename is supplied.
Any files that don't match the SeisNet filename pattern are ignored.

The author of cvt2segd gratefully acknowledges the permission of
both SSI and Landmark graphics to contribute this software to the SU package.