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CWP/SU:Seismic Un*x Past, Present, and Future. EAGE Workshop: Open Source Software in E & P Vienna, 11 June 2006. J ohn Stockwell, Research Associate Center for Wave Phenomena Colorado School of Mines Golden Colorado USA. http://www.cwp.mines.edu/cwpcodes. Acknowledgment of Support.
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CWP/SU:Seismic Un*x Past, Present, and Future EAGE Workshop: Open Source Software in E & P Vienna, 11 June 2006 John Stockwell, Research Associate Center for Wave Phenomena Colorado School of Mines Golden Colorado USA http://www.cwp.mines.edu/cwpcodes
Acknowledgment of Support • CWP Consortium Project on Inverse Problems in Complex Structures • Society of Exploration Geophysicists Foundation • Gas Research Institute
Topics • What SU is and is not • History of SU • Current issues • Future plans
Issues • role of SU in geophysics • structure of the code • human factor • ``rules'' of open source
What Seismic Unix is • open source • education and research • CWP's home environment • instant and personal environment
What Seismic Unix is not • not GUI driven • not a lot of 3D • neither perfect nor complete • not a substitute for commercial software • ...but fills a role that commercial software cannot fill
Who uses SU? • academics • government researchers • small independent contractors • researchers in larger companies
Uses of SU • seismic trace manipulation • data processing/modeling • prototyping/software development • quick look at data • non-seismic (i.e. GPR radar)
Usage Statistics • approx. 3300+ install messages • 2 install messages every 3 days • 3-10 downloads per day • 524 active listserver members • 68 country codes
What makes SU SU? • written in C • getpars • selfdocs • readable source code • SEG Y data structure • Unix or Unix-like platform
The SEG Y data format • 3200 byte EBCDIC reel indentifier • 400 byte binary reel header • 240 byte binary trace header • data in 32 bit IBM tape format • Repeat trace header and data
The SU data format • 240 byte binary trace header • data native binary floats • Repeat trace header and data
SY and the origins of SU • SY 1979-1984 Einar Kjartansson (at Stanford) • SY 1984-1986 Shuki Ronen • SU 1986 Jack K. Cohen (at CSM) • SU 1987 Jack takes SU to Texaco
SU expands • 1989-1993 Jack Cohen and Dave Hale • 1989-1996 Jack Cohen and John Stockwell • 1992 first Internet release of SU • 1996-present
Some ``rules'' of open source • stress portability and readability • port to many platforms • enlist the aid of the users • take users needs under consideration • know who your users are and how they use your code
Benefits of open source • clean house • new colleagues and partners • bug fixes and extensions • new codes • worldwide presence
Challenges • ``no charge''=``no value'' • pressure from users • grandiose suggestions • project expansion • some contributed code not open source
Remedies • ``open source''=``instant standard'' • separate need from want • ask for an example • keep your project in its scope • require references for contributed code
More ``rules'' • minimize dependency on 3rd party items • avoid relying on ``special features'' • give credit to contributors • demos should accompany code submissions • stress stability and longevity over novelty
Current and Future issues • SEG Y Rev 1 support • 3C • 3D • cluster • update license?
The SEG Y Rev 0 data format • 3200 byte EBCDIC reel indentifier • 400 byte binary reel header • 240 byte binary trace header • data in 32 bit IBM tape format • ...Repeat trace header and data
Proposed solution, SU Rev 1 • 512 byte binary header • data in big-endian 32 bit • ...backward compatability to SU Rev 0 • ...with MPI 3D, 3C, and cluster follow directly
Concluding remarks • SU is here to stay • Your help and feedback are welcome • Thank you!