20.1 SAC2000

SAC2000 (seismic analysis code) is currently developed by Lee Minner and Peter Goldstein (Goldstein, 1999). SAC is not distributed with SEISAN, information on SAC can be obtained from the SAC homepage (http://www-ep.es.llnl.gov/www-ep/esd/seismic/sac.html). The main features of SAC include general arithmetic operations, Fourier transforms, three spectral estimation techniques, IIR and FIR filtering, signal stacking, decimation, interpolation, correlation, and seismic phase picking. SAC also contains an extensive graphics capability. With SAC it is possible to write macros, which helps to process large amounts of data. The SAC format is used in several research oriented programs. SAC can be started from EEV using the command `sac'. EEV will start the WAVETOOL program to convert the data to SAC and then execute the command sac. In case your sac executable is called sac2000, it is necessary to rename it (to sac) or alternatively to create a link in either the SEISAN PRO directory or the SAC bin directory. This is done for example by the command :
ln -s /sac/bin/sac2000 /sac/bin/sac
Since the SAC format is a single trace format, the SEISAN multichannel files are split into single trace files. The station and component names are included in the file name and the suffix `SAC' is added to all SAC files. For both systems, waveform data can be converted to the respective format outside EEV using WAVETOOL, GSESEI or SACSEI, and the programs can be started without using EEV.