Thread: How to deal with vertical components with cmpinc 180

Started: 2021-08-20 19:25:09
Last activity: 2021-08-22 21:24:04
Topics: SAC Help
Marta Pischiutta
How to deal with vertical components with cmpinc 180
2021-08-20 19:25:09
Good evening,
I have recently downloaded some old earthquakes which report in the header of the Vertical component this value for cmpinc (180), that probably means that this component is reversed.
How may I rotate only one component using the command “rotate"?
Thank you in advance
Marta

  • Félix Rodrigo Rodríguez Cardozo
    Re: How to deal with vertical components with cmpinc 180
    2021-08-22 17:19:07
    Hi Marta,

    If I understood your issue, in your case since is the vertical component rotated 180º, I guess multiplying your seismogram by -1 would be enough, that is "r your_vertical_component.HHZ; mul -1".

    I hope it helps, and I apologize in advance if you already thought of this simple solution.

    Best regards,

    Félix
  • Martha Savage
    RE: How to deal with vertical components with cmpinc 180
    2021-08-22 18:15:13
    Hi Marta,

    Multiply the vertical trace by -1.

    Martha

    Martha Savage
    Professor of Geophysics, SGEES
    Victoria University of Wellington
    Te Whare Wananga o te Upoko o te Ika a Maui
    Cotton 529
    Box 600, Wellington 6140
    New Zealand

    Email: Martha.Savage<at>vuw.ac.nz
    DDI: +64 (0)4 463-5961
    Mobile: +64 (0)21-262-7516
    Makere ana nga here


    -----Original Message-----
    From: sac-help-bounce<at>lists.ds.iris.edu <sac-help-bounce<at>lists.ds.iris.edu>
    Sent: Monday, 23 August 2021 4:10 AM
    To: SAC Help <sac-help<at>lists.ds.iris.edu>
    Subject: [IRIS][sac-help] How to deal with vertical components with cmpinc 180

    Good evening,
    I have recently downloaded some old earthquakes which report in the header of the Vertical component this value for cmpinc (180), that probably means that this component is reversed.
    How may I rotate only one component using the command “rotate"?
    Thank you in advance
    Marta


    • Marta Pischiutta
      Re: How to deal with vertical components with cmpinc 180
      2021-08-22 21:24:04
      Thank you Martha
      I already did that after submitting the request in the Iris but wanted to know if there is a command like rotate involving only the vertical component !
      Cheers

      ________________________
      Marta Pischiutta, PhD
      Istituto Nazionale di Geofisica e Vulcanologia,
      Department of Seismology and Tectonophysics
      Address : via di Vigna Murata 605
      00143, Roma
      Ph. (Office) : 0039 06 51860544
      Ph. (Mobile) : 0039 328 7110305
      Skype: marta.pischiutta
      __________________________

      Il giorno 22 ago 2021, alle ore 20:21, Martha Savage (via IRIS) <sac-help-bounce<at>lists.ds.iris.edu> ha scritto:

      Hi Marta,

      Multiply the vertical trace by -1.

      Martha

      Martha Savage
      Professor of Geophysics, SGEES
      Victoria University of Wellington
      Te Whare Wananga o te Upoko o te Ika a Maui
      Cotton 529
      Box 600, Wellington 6140
      New Zealand

      Email: Martha.Savage<at>vuw.ac.nz
      DDI: +64 (0)4 463-5961
      Mobile: +64 (0)21-262-7516
      Makere ana nga here


      -----Original Message-----
      From: sac-help-bounce<at>lists.ds.iris.edu <sac-help-bounce<at>lists.ds.iris.edu>
      Sent: Monday, 23 August 2021 4:10 AM
      To: SAC Help <sac-help<at>lists.ds.iris.edu>
      Subject: [IRIS][sac-help] How to deal with vertical components with cmpinc 180

      Good evening,
      I have recently downloaded some old earthquakes which report in the header of the Vertical component this value for cmpinc (180), that probably means that this component is reversed.
      How may I rotate only one component using the command “rotate"?
      Thank you in advance
      Marta


      ----------------------
      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/


NSF SAGE Facility has been certified as a trustworthy data repository by the CoreTrustSeal Standards and Certification Board
15:43:08 v.b4412d20