rayinvr

Group:

Authors:

Igor Morozov, 6/97, revised 10/98

2D seismic ray-tracing and gravity modeling

Originally an interface for Colin Zelt's ray-tracing RAYINVR program, now this tool provides a model builder and editor for TRACER2 and inversion programs. The tool performs the following operations:

1. Inputs, checks, and edits Zelt's models.
2. Creates tx.in files and/or runs RAYINVR program.
3. Allows plotting of the model using PLOTMTV, GMT, and the GUI<>
4. Performs ray tracing using TRACER2, and depth conversions using DEPCON.
5. Performs ray tracing in pseudo-2D models associated with crooked lines on ellipsoidal Earth.
6. Creates 2D/3D interactive ray-tracing sessions (by using tool GUI).

If this model is used to run the RAYINVR program, it first copies the input files into tx.in, r.in, and v.in, runs Zelt's code, and ten renames the output *.out files into the files corresponding to the prefix (model name) provided in the first parameter of this module's call. Thus we provide individual model names instead of the ambiguous r.in, tx.in, etc.

If any travel time preprocessing is necesary (e.g., to obtain coordinates, add/remove reduction, to apply statics), it can be done using TABMATH or other travel-time tools.

In some layer-editing operations, a "layer group" name may be specified. This name is constructed as follows:

• '1-3' means the layers from 1 to 3, etc.
• '2' means just the second layer.
• For all layers from layer 3 to the bottom of the model, use '3-*'.
• For all layers from the top to layer 5, use '*-5'.
• Finally, you may specify all layers as '*', or '*-*'.

By using DEFINE command, you may build meaningful names for these groups, for example:

*define crust 1-5 mantle 6-* allmod * ...

All model generation and editing operations are performed during EDIT phase. However, the module may have a "second personality" during EOF phase, and can save the model in a different format at that time.

Note that SAVE during the first call saves the model immediately, e.g., duting the editing operations, and any number of times. Durinng the later (EOF) calls, RAYINVR can only save the model, but cannot edit it. All editing commands will be ignored in these calls.

Using crooked lines

To make RAYINVR work in crooked-line geometry, the line of midponts (with which the model cross-section is associated) needs to be provided in a call to tool PROJECT preceding RAYINV.

Module call format: