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Important Points and Assumptions
The retrieved NOAA T-Phase data are stored into
a CSS output file with the suffix CSS;
the file is binary. A CSS header file with the suffix wfdisc is
also created; this file is ASCII. Therefore, if T-Phase data from 3
different locations were requested, there will be 3 CSS data
files and 3 wfdisc header
files. The wfdisc header
file will not contain the true hydrophone location and other system
information, such as the hydrophone sensitivity. For retrieving
that information, use the NOAA
internal format output option.
It is assumed that users who choose the CSS format
as the output option know how to work with CSS binary output or have
software to read the CSS files. Therefore, only some essential
information is provided here.
CSS Header (*.wfdisc) File Structure
A CSS header file with a suffix wfdisc is
an ASCII file. Each record is 234 characters long. The wfdisc
file describes the contents of 1 CSS file.
When the retrieved NOAA T-Phase data are stored into a CSS file, its
header file will contain only 1 record. The contents of the header record
can be found in the Appendix C, Table: C-13 of the following document:
http://www.pidc.org/rdss/documents/user_guide/CMR00_14.pdf
Instructions for Reading CSS Data Files
The following codes are provided by Dr. DelWayne R. Bohnenstiehl
of Lamont-Doherty
Earth Observatory, Columbia
University. Note it is assumed users know either MatLab or SAC2000 and
where to get references for details.
By MatLab
Quick View Options:
fd =fopen('file.w','r','l'); %%% r- opens file for reading; l- Little Endian
signal=fread( fd, 'int16' ); %%% signal - vector of signal amplitude;
int16 - specifies 16-bit data
By SAC2000 Program
(on a little endian machine)
sac2000 ### starts sac2000
readcss file.wfdisc ### read the wfdisc and load corresponding file.w
plot ### plot the waveform
listhdr
Converting CSS to Other Data Formats
The ORFEUS
Seismological Software Library provides a wide range of programs that are
able to convert CSS to other formats such as SAC and SEED. |
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