Thread: ERROR SAC

Started: 2022-04-01 13:00:10
Last activity: 2022-04-05 12:48:42
Topics: SAC Help
cristina caricato
2022-04-01 13:00:10
Dear SAC help,
I am an italian student who is working with sac for my master's degree
thesis.
I am writing to you because I am experiencing a problem in using sac.
I read the waveforms, I open the phs file with ohpf, I pick the P and S
phases, I save the picking typing H on the waveforms, and, lastly, I save
the file phs with whpf. However, when I open the file phs it is an empty
file.
The A, KA, T0 and KT0 are correctly written in the header.
I really don't know the reason for which the phs file is empty.
How can I solve this problem? Could you please help me?
I am attaching an event.
Best regards
Cristina Caricato

  • George Helffrich
    2022-04-05 12:48:42
    Dear Cristina Caricato -

    It is almost impossible to wind up with an empty HYPO file when SAC is finished with it. That’s because SAC’s close command for HYPO files always writes an instruction card “10” at the end. (SAC writes this even if you forget to close the HYPO file and you quit SAC.) If your file is really empty, then it means that you and SAC disagree on what the name of the file is, and you are looking at the wrong place (wrong directory) or file name (perhaps with spaces in it or with some special, non-ASCII characters in it). Use the Unix “ls -lt” to see what files were most recently changed after you finished with SAC to find the one it wrote to.

    Otherwise, the only thing that would prevent SAC from writing picks to the HYPO file is if the ZERO time in the file is incomplete. I checked a few of the files that you sent (the Z components) and the ZERO times look OK, however. There are also picks in those files for P and S.

    Whenever SAC writes a line to the HYPO file after PPK, it prints the text on your screen with “*” followed by the text of the HYPO line. If you didn’t see that, SAC didn’t write the HYPO file and you probably typed “G” rather than “H” after you finalized your picks. (Even if you did type “G”, you can still type “H”.)

    SAC will also write the HYPO file during the PPK command if it replots a trace with unwritten picks made in it. This might happen if you expand a time interval (using “X”) and/or go back to a previous window (using “O”).

    Hope this points you in the right direction to solving your picking problems.

    On 4 Apr 2022, at 17:18, cristina caricato (via IRIS) <sac-help-bounce<at>lists.ds.iris.edu> wrote:

    Dear SAC help,
    I am an italian student who is working with sac for my master's degree thesis.
    I am writing to you because I am experiencing a problem in using sac.
    I read the waveforms, I open the phs file with ohpf, I pick the P and S phases, I save the picking typing H on the waveforms, and, lastly, I save the file phs with whpf. However, when I open the file phs it is an empty file.
    The A, KA, T0 and KT0 are correctly written in the header.
    I really don't know the reason for which the phs file is empty.
    How can I solve this problem? Could you please help me?
    I am attaching an event.
    Best regards
    Cristina Caricato
    <MN.WDD..HHZ.sac><MN.WDD..HHN.sac><IV.HVZN..HHZ.sac><MN.WDD..HHE.sac><IV.HVZN..HHN.sac><IV.HVZN..HHE.sac><IV.HPAC..HHZ.sac><IV.HPAC..HHN.sac><IV.HPAC..HHE.sac><IV.HAGA..HHZ.sac><IV.HAGA..HHN.sac><IV.HAGA..HHE.sac><IV.CROCE..HHN.sac><IV.CROCE..HHE.sac><IV.CROCE..HHZ.sac>
    ----------------------
    SAC Help
    Topic home: http://ds.iris.edu/message-center/topic/sac-help/ | Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu

    Sent from the IRIS Message Center (http://ds.iris.edu/message-center/)
    Update subscription preferences at http://ds.iris.edu/account/profile/



    George Helffrich
    george<at>elsi.jp


Page built 02:38:18 | v.eb57efaa