4.3.10.1.3 SEG-Y Examiner

SEG-Y Examiner can be launched by pressing on icon in Import SEG-Y Data window. SEG-Y Examiner allows to check essential information about the data by inspecting text, binary and trace headers as well as plotting seismic traces for QC. It is recommended to use this tool to check your SEG-Y import set-up and adjust it if needed.

SEG-Y Examiner can stay open during import.

File header information:

• Text (EBCDIC) header (3200 bytes: 40 lines, 80 symbols each): free-format text commonly containing processing history, data ranges, and non-standard trace header byte locations.
• Binary header (400 bytes): scroll down to see a summary of non-zero values in the binary header which commonly includes info about data format, SEG-Y revision and Z-range (sampling rate and number of samples).

Save textual header to a file.

Trace header information:

• Table:
  • trace header byte numbers and shortened field names are shown in the first column;
  • trace header values of examined traces are shown in the following columns.
• Graph: plot between any individual trace header and the number of random traces examined is a very good tool to visualize its range and inspect for any discrepancy:
  • highlight any trace header (a row) in the table to see its graph versus consecutive trace number;
  • extended explanation of a highlighted trace header is given above the graph (please see SEG standards for more details);
  • Range: [...,...]: values of a highlighted trace header in the examined traces.

Use the lateral scroll bar at the bottom to locate the headers with changing values. Those might be trace numbers, crossline numbers, offsets, coordinates etc. Inline numbers are often written to the bytes preceding crosslines. Most 3D data is inline sorted, therefore choose sufficient number of traces to examine (several times more than the number of crosslines per inline) in order to see the increasing inline numbering.

Display traces: It is strongly recommended to always view examined traces in the 2D viewer.

Show histogram of sample values.

Rubberband zoom Zoom in Zoom out Cancel zoom Flip left/right Save image Print image Set display parameters