Retrieving Waveform Data From SCEDC via STP
Waveform data is easiest to retrieve via the STP interface. First check if the STP client has already been made available on your system by trying to execute. If it is not available you will need to get a copy of the client from the SCEDC ftp site. For example if your are on a Unix, Linux or Mac OS-X system get the file stpX.X.tar where X.X is the largest number available. Untar this file and follow the instructions in the README file. The installation is simple and has no configuration parameters. If you are on a windows computer use the recompiled "STP.exe" program.
Start the stp program simply type stp with arguments.
The first to learn is help
STP> help -- get a list of commands
STP> help win -- get the manual page on the "win" command To get waveform data use the "win" command as follows
STP> verbose <- set once per session, instructive to see what is happening
STP> win NR NR76 BHZ 2003/12/03,03:10:12.12003/12/03,03:15:12.1
This will retrieve 5 minutes of the waveform NR.NE76.BHZ starting at the specified time. If you issue the command
STP> win NR % BH_ 2003/12/03,03:10:12.1 +5m
you will get all stations of the NR network ('%' is the wild card), and all three compoents of the 'BH' channel ('_' is the wild character). Note that the end time can be specified as a duration (indicated by the leading '+' sign). The units are m=minutes, s=seconds, h=hours, and d=days.
You can use STP to look for suitable teleseismic events with the 'event' command.
STP> event -t0 2002/04/20 2004/06/01 -lat 22 32 -lon -117 -106 -mag 5.0 9.0
and this will produce a list of events.
To gracefully exit STP, type
The above example will delivery the data to your computer in SAC format in the directory that you start STP in. You can change the format, and the directory. The byte-order of the data is suitable for the computer on which you execute stp (so don't execute STP on a linux computer for use on a SUN computer unless you explicitly force the bytes to swap).