Model 4: Build, Acquire a Line, Display Gathers, QC
In the previous two chapters, we developed three simple models and used them to acquire 2-D lines of seismic data. In this chapter, we combine some of the attributes of those models to create a fourth model and use the model to acquire a 2-D line of seismic data
In the following two sections, we explain the model and acquisition scripts in detail; you do not have to be familiar with the related scripts that are in the previous two chapters.
The next three sections of this chapter explain how to build the model, acquire seismic data, and view selected gathers. While those sections are important, the last two sections about quality control (QC) are equally important. The QC sections explain how you can acquire survey information and seismic data from selected portions of the model. You can examine preliminary survey information and seismic data to increase your confidence in your model and your acquisition script before spending time acquiring the full seismic data set.
As with previous models, Model 4 layers are homogeneous and isotropic. Each layer has a single acoustic (P-wave) velocity. Let's examine script model4.sh. The numbers on the left are added for discussion; they are not part of the script.
This script can be divided into sets:
System: Line 1 invokes the shell, line 5 turns on messages, and line 64 exits the shell.
Variables: Line 8 lets us vary the number of each run as we perfect the script (2a, 2b, etc.). This number becomes