A_reference_frame

Table of Contents

• Reference Frame Convention
  • Seismogram outputs

Reference Frame Convention

The code uses the following convention for the Cartesian reference frame:

• the $x$ axis points right (i.e., East)

• the $z$ axis points up (i.e., North).

Seismogram outputs

The seismogram output directions are given in Cartesian $x$/$z$ directions. They can be rotated (from the direction of positive $z$, i.e. from the North) if needed using a flag defined in the Par_file.

For the labeling of the seismogram channels, see Appendix [cha:channel-codes]. Additionally, we add labels to the synthetics using the following convention: For a receiver station located in an

elastic domain:

• semd for the displacement vector

• semv for the velocity vector

• sema for the acceleration vector

acoustic domain:
(please note that receiver stations in acoustic domains must be buried. This is due to the free surface condition which enforces a zero pressure at the surface.)

• semd for the displacement vector

• semv for the velocity vector

• sema for pressure which will be stored in the vertical component Z. Note that pressure in the acoustic media is isotropic and thus the pressure record would be the same in the other two component directions. We therefore use the other two seismogram components to store the acoustic potential in component X (or N) and the first time derivative of the acoustic potential in component Y (or E).

The seismograms are by default written out in ASCII-format to the OUTPUT_FILES/ subdirectory by each parallel process.

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This documentation has been automatically generated by pandoc based on the User manual (LaTeX version) in folder doc/USER_MANUAL/ (Aug 26, 2024)