Tape Formats of Seismic DataOnce upon a time, there was many different tape formats used for seismic data acquisition and processing, for example SEG-A, SEG-B, SEG-C, SEG-D, SEG-X, and SEG-Y. Because every manufacturer of recording equipment and processing contractor had their own format, Society of Exploration Geophysicists (SEG) helped us to make technical standards for tape formats. These technical standards made the number of field formats had rapidly decreased over the last few years.

Before we discuss more detail about some specific formats, we have to know the common general layout of all tape formats.

Tape Format General Layout

Tape/Line Header: A general header that identifies the tape, or this part of the tape
Record Header: A header for each “bath” of data (for example, one field record) on the tape.
Scan/Trace Header: A header for the individual trace (de-multiplexed) or scans (multiplexed) on the tape.
Seismic Samples: The seismic samples themselves, in whatever format, for example:
1: IBM floating point, 4 byte (32 bits)
2: two’s complement integer, 4 byte (32 bits)
3: two’s complement integer, 2 byte (16 bits)
5: IEEE floating point, 4 byte (32 bits)
8: two’s complement integer, 1 byte (8 bits)

This sequence is repeated along the tape, with an “End-of-file” (a particular code) recorder at the end of each file on the tape. A file may consist of many individual traces or records, and the tape may consist of many different files.

For this time, SEG-D is the most common current format for seismic acquisition and SEG-Y is for seismic processing. We will discuss more detail about SEG-D and SEG-Y later.

References:
Seismic Data Processing Interactive Tutorial
SEG Technical Standards
Seismic Unix