Creating a Base Map from BSEGY Headers

Since the shot and receiver locations are in the BSEGY headers, we can use program bcad to build a basemap by extracting this information and generating a CAD data exchange format file, *.dxf. For example,


bcad k008.seg 1  1  2.0



creates file bcadk008.dxf. It is a simple “point” file with 2.0 meter labels. All three recording files use the same geophone stations in this example, so the only difference in running bcad on the 3 files will be the source location. If you download the open source program, dxf2fig, you can convert the *.dxf files to xfig format files. These can then be edited in xfig to build a base map. I downloaded dxf2fig from http://homepage.usask.ca/~ijm451/fig/. (version 2.13). There are other versions at other websites, use a search engine if the location changes after this writing. I have included an edited version based on the two files k008.seg and k009.seg. the map is shown in Figure 27. Alternatively, I recommend Qcad to work with *.dxf files directly. Qcad is available from https://qcad.org/en/.

Figure 27: Base map for refraction survey along road shoulder.
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