specfem2segy

specfem2segy.py is a Python3 code for generating SEGY format common shot gathers from ascii format seismograms output into the OUTPUT_FILES folder by SPECFEM2D.

*Channel number and offset are the only SEGY trace headers assgined. Byte ordering is big endian.

This code requires the following Python libraries to be already installed in your system.

• Numpy
• Pandas
• Obspy
• Matplotlib

For convenience, parameters required for generating the common shot gather in SEGY format can be parsed through the command line.

Usage:

python3 specfem2segy.py [arguments]

Arguments:

Argument	Required	Description
-h, --help		show help
--df	No	Folder where the output ascii seismograms from SPECFEM2D are saved. Defaults to 'OUTPUT_FILES/'. Note that you have to include the trailing '/' after the name of the folder.
--stype	Yes	Seimograph type. 'd' for displacement, 'v' for velocity.
--scomp	Yes	Seimograph component. 'Z' for vertical, 'X' for radial.
--stbeg	No	Identification number for the first station in the ascii seismogram files. Defaults to 1.
--stend	Yes	Identification number for the last station in the ascii seismogram files. You can use a number less than the number of seismogram files for smaller gathers
--offbeg	Yes	Source-receiver offset (in km) for first station. Use negative values for stations to the west of the source.
--offend	Yes	Source-receiver offset (in km) for last station. Use negative values for stations to the west of the source.
--offsp	Yes	Spacing between adjacent stations (in km).
--resamp	No	Resample rate for the output SEGY file. Defaults to 200 Hz.
--plotpdf	No	Whether to plot a pdf file of the gather for checking. Use True for plotting. Defaults to False (pdf not plotted).
--outname	Yes	Name for the output segy file. The same name will be used for the output pdf file if --plotpdf True.