Saving an internal file as a standard SEG-D file

SEG-D is the standard raw field recording format used by seismic acquisition instruments. Most workflows only read SEG-D, converting it to SEG-Y on import. This module does the reverse: it writes an internal file back out as a genuine SEG-D file, so it can be handed off to a client or downstream system that expects the SEG-D format, or round-tripped back through this software using "Convert SEG-D to SEG-Y".

Unlike "Save SEG-Y", this module does not require the whole gather to be loaded into memory first: it takes a trace header list plus a read handle on the source data, and pulls the actual samples on demand in batches as it writes. One SEG-D record is emitted per FFID (one record per shot), so traces belonging to the same shot are grouped together automatically in the output file.

Input DataItem -

Data handle - the read/write handle on the source data file that samples are pulled from on demand as the SEG-D file is written.

Trace vector - the list of traces (with headers) to be written to the output SEG-D file.

SEG-D file name - provide the path and file name of the output SEG-D file. Extension should automatically be assigned as ".segd" or ".sgd".

Rewrite file - overwrites the output file if it already exists. By default, TRUE (Checked).

SEG-D revision - the SEG-D format revision written to the output file. Currently fixed to "SEG-D Revision 2" (no other revision is available yet).

Sample format - the trace sample encoding written to the output file. Currently fixed to "8058 (IEEE, 32-bit demultiplexed)" — 32-bit IEEE floating point, big-endian, one trace after another (no other sample format is available yet).

Save only live traces - skips dead/killed traces instead of writing them to the output file. By default, TRUE (Checked).

Read bulk size - number of traces read from the source data handle per batch while writing. By default, 100000 traces, minimum 1000. Lower this if the module uses too much memory while writing very large datasets; raise it to reduce the number of read batches on fast storage.

Output

Number of traces written - displays the total number of traces written into the output SEG-D file.

Output file name is provided within the parameters tab and there is no output data generated as a connection/reference for next modules. There are no action items available for this module so the user can ignore it.