SEG-Y Rev 2.0 Conformance
S-01622
As a Tullow Geophysicist I want SEG-Y revision 2 conformance for interoperability reasons and so as to support the new features such as X.
Pre-Dev Notes:
Changes from rev 1 to rev 2:
- Provide for up to 65535 additional 240 byte trace headers with bytes 233-240 of each trace header reserved for trace header names
- Allow up to 2^32 –1 samples per trace
- Allow arbitrarily large and small sample intervals
- Permit up to 264–1 traces per line and 232–1 traces per ensemble
- Support additional data sample formats, including IEEE double precision (64 bit)
- Support little-endian and pair-wise byte swapping to improve I/O performance.
- Support microsecond accuracy in time and date stamps
- Support additional precision on coordinates, depths and elevations (especially useful for lat/long and UTM coordinates) and more options for coordinate reference system specification
- Require Extended Textual File Header stanzas to begin at 3200-byte boundaries and removed 40 80-byte line restriction
- Allow stanzas to appear after the last data trace
- Provide flexible trace header mapping options via Extended Textual File Headers. Because of this ability, we remove almost all “mandatory” and “highly recommended” header entry designations
- Allow XML-based Extended Textual File Header and Trailer stanzas for ease of machine encoding and decoding
- Include depth, velocity, EM, gravity and rotational sensor data
Current Status:
- Points 1-4: PIOL already supports
- Point 5: Would need to add IBM_to_double
- Point 6: Add to encoding file
- Point 7: need to see if PIOL does this already
- Point 8-9: PIOL already does this
- Point 10: ?????
- Point 11:
- Point 12: In theory PIOL supports writing XML-based Extended Textual File Header and Trailer stanzas but there is no encoder
- Point 13: PIOL could do this (we don't have a rule currently to set these header values) General note: Rev 2 standard has been exclusively used for development since July 2017 (MF)
Rev 1 was used before March 2017. Checking which standard a file is in, is not implemented. Compare rev 1 & rev 2 thoroughly and implement appropriately.
Implementation Notes:
ADDME
System Test Changes:
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Bug Fixes:
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C++ API Changes:
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C API Changes:
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Success Criteria:
ADDME
CREATED ON - 05/04/2017
Edited by Christopher Werner