Thread: ppk questions

Started: 2019-08-02 16:30:13
Last activity: 2019-08-03 19:45:49
Topics: SAC Help
Igor
2019-08-02 16:30:13
Hello,

I have 2 questions about the ppk.
Could you please help me to find out the answers?

1) When the ppk is enabled, after every mouse click, the time is printed in
the upper left corner. Is there a way to place a marker (a bw or color
symbol ) on the seismogram where the mouse click was done?

2) Is there a way to save the ppk picks in a text file (not to see them on
the screen only)?

Thank you ,
Igor

  • George Helffrich
    2019-08-03 08:51:49
    Dear All -

    1) If you pick with A, P, S or F a labeled mark will be left on the trace. However, these picks change the file header, so if you don’t want them made permanently, don’t write the header out.

    2) The SAVELOCS option to PPK will save the locations of the mouse, when picked with L, in blackboard variables that may be retrieved after the PPK command. You can write those into a text file if you want.

    To my knowledge, SAC only reports a cursor position to the screen when L is used in a PPK operation. Mouse clicks don’t mean anything.

    On 3 Aug 2019, at 00:31, Igor <stubailo<at>gmail.com> wrote:

    Hello,

    I have 2 questions about the ppk.
    Could you please help me to find out the answers?

    1) When the ppk is enabled, after every mouse click, the time is printed in the upper left corner. Is there a way to place a marker (a bw or color symbol ) on the seismogram where the mouse click was done?

    2) Is there a way to save the ppk picks in a text file (not to see them on the screen only)?

    Thank you ,
    Igor

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    George Helffrich
    george<at>elsi.jp


  • Geo .
    2019-08-03 19:45:49
    Hi Igor,
    Here's what I would do within a macro or a shell script. Assume that you
    are picking two phases in the same seismogram and writing the arrival times
    into T1 and T2 headers.

    * read files using a wild card
    DO FILE WILD *.SAC
    READ $FILE

    * Show pick "A" by a cross (c) with width (w) 0.1 & height(h) 0.3
    PICKS T1 C W 0.05 H 0.3
    PLOTPK

    * Show pick "B" by a cross (c) with width (w) 0.1 & height(h) 0.3
    PICKS T2 C W 0.05 H 0.3
    PLOTPK

    WRITE OVER

    ENDDO


    Now you can extract your headers within a shell script, for example, using
    saclst:
    pick_file.txt
    saclst T1 T2 f my_file.SAC | awk '{ print $2,$3 }' >> pick_file.txt

    Januka

    Januka Attanayake
    Research Fellow | Earthquake Seismology
    Homepage: *https://sites.google.com/site/janukaattanayake
    https://sites.google.com/site/janukaattanayake*

    School of Earth Sciences | McCoy Bldg. 200
    University of Melbourne | Parkville 3010 VIC
    Australia




    On Sat, 3 Aug 2019 at 09:32, Igor <stubailo<at>gmail.com> wrote:

    Hello,

    I have 2 questions about the ppk.
    Could you please help me to find out the answers?

    1) When the ppk is enabled, after every mouse click, the time is printed
    in the upper left corner. Is there a way to place a marker (a bw or color
    symbol ) on the seismogram where the mouse click was done?

    2) Is there a way to save the ppk picks in a text file (not to see them on
    the screen only)?

    Thank you ,
    Igor

    ----------------------
    SAC Help
    Topic home: http://ds.iris.edu/message-center/topic/sac-help/ |
    Unsubscribe: sac-help-unsubscribe<at>lists.ds.iris.edu

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05:10:35 v.f0c1234e