Reader Directives

This section contains the directives that are processed by the SEG-Y reader.

The suffixes shown are prefixed by the current <ReaderKeyword> in a mapping file. By default, the <ReaderKeyword> for the SEG-Y reader is SEGY.

DATASET

This directive is the name of one or more SEG-Y files.

SEG-Y files can have any extension; however, common extensions are .segy or .sgy.

Required/Optional

Required

Mapping File Syntax

SEGY_DATASET /usr/data/mysegyfile.segy

Workbench Parameter

Source SEG-Y File(s)

COORDINATE_POSITION

This directive specifies the byte offset of the coordinate values in the binary trace file.

Values

The coordinate values are stored as two 4-byte values. Therefore, if the byte offset of 81 is specified, the X coordinate will be read from locations 81 to 84, and the Y coordinate will be read from locations 85-88.

Required/Optional

Optional

Mapping File Syntax

SEGY_COORDINATE_POSITION 81

Workbench Parameter

Stored coordinate location

COORDINATE_FORMAT

This directive specifies the binary encoding that the reader will use to interpret the coordinate values in the binary trace header.

Values

INT | IEEE | IBM

INT specifies that the stored value is encoded as a signed integer. IEEE specifies that the stored value is encoded as an IEEE floating point number. IBM specifies that the stored value is encoded as an IBM floating point number.

Required/Optional

Optional

Mapping File Syntax

COORDINATE_FORMAT INT

Workbench Parameter

Stored coordinate format

DECODE_EBCDIC

This keyword specifies whether the reader will interpret the textual header as being in the EBCDIC encoding and will transcode the textual header into ASCII.

Required/Optional

Optional

Mapping File Syntax

DECODE_EBCDIC YES