Finding Aid to the Papers of R. Craig Walker
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This collection is currently being processed and the finding aid is incomplete. Contact the Archivist for additional information.
Location of collection: National Radio Astronomy Observatory, Archives, 520 Edgemont Rd., Charlottesville, VA. Phone: 1-434-296-0203, email: archivist at nrao.edu Title and dates of the collection: Papers of R. Craig Walker, 1971-****. Collection is currently being processed. Size of the collection: Collection is currently being processed. Papers/Records created by: Walker, R. Craig, (1948- ) Short description of collection: Materials related to the VLBI Consortium/Network Users Group and management of VLBI at NRAO; pre-VLBA documentation related to VLBI; planning, development, siting, configuration, and management of the VLBA.
Biography: Robert Craig Walker (Craig) received a BA degree in physics and mathematics from the University of California, San Diego in 1971 and a PhD in physics from the Massachusetts Institute of Technology in 1977. He was a post-doctoral fellow at Caltech from 1977 to 1979, after which he joined the NRAO staff in Charlottesville, Virginia. At the end of 1984, he followed the Very Long Baseline Array (VLBA) project, then under construction, to Socorro, New Mexico. He retired in 2015, but continued as an Emeritus Scientist to work on some of his observational projects and, eventually, to use his VLBA expertise in work on the ngVLA configuration. Walker's scientific research has focused on imaging astrophysical masers, implementing the use of aperture synthesis imaging for spectral line Very Long Baseline Interferometry (VLBI) data, and VLBI imaging and monitoring of jets, especially the inner jet structure just outside the core region. Throughout his career, Walker has been an active participant and leader in VLBI work, both within NRAO and with the U.S. VLBI Network and Consortium. He served in a scientific oversight role for many technical aspects of the VLBA project. He led the configuration group and was the primary architect of the overall configuration. A shared interest in bicycling with NRAO Associate Director and VLBA Project Director Hein Hvatum served him well as they spent endless hours riding the back roads of Albemarle County VA discussing details of the VLBA design and operation. As VLBA antennas became available, Walker was deeply involved in testing and early operations. He wrote, and supported until retirement decades later, the scheduling program still used for most astronomical VLBI worldwide, and also wrote much of the software used for measuring pointing and gain on the VLBA antennas and for verifying the quality operation of the telescope. He was the primary person ensuring that the VLBA worked well, making regular observations to update the calibration and pointing parameters and to confirm the data quality, and then working with operations and engineering staff to understand and correct any problems found. His work on VLBI configurations included options for SKA configurations and for the proposed New Mexico Array (EVLA phase 2). In retirement, he guided an improved configuration for ngVLA Mid, and ngVLA Long is basically Walker's VLBA configuration with some modifications, most made following his input. Walker is a member of the American Astronomical Society, URSI Commission J, and the International Astronomical Union. He was an at large member of the U.S. VLBI Consortium from 1984 to 1987 and was an NRAO representative on that organization from 1987. He was the final Executive Officer of the U.S. VLBI Consortium from 1989 to 1993, during the period of the transition to the VLBA. He was a member of the Arecibo Scientific Advisory Committee from 1987 to 1989, the QUASAT Working Group, and was an NRAO representative to the US SKA Consortium from 2003 to 2006. [Biographical note written by Craig Walker, edited by Ellen Bouton.] Accession history: Papers donated by Walker in May 2026. Access to collection: No restrictions. The Archives are open part-time; contact the Archivist for appointment. Restrictions on use of collection: None. Publication rights: Copyright has been assigned to The National Radio Astronomy Observatory. All requests for permission to publish or quote from manuscripts must be submitted in writing to the Archivist. Preferred citation: National Radio Astronomy Observatory/Associated Universities, Inc. Archives, Papers of R. Craig Walker, <series/unit/subunit/box #>. After the initial citation, abbreviations may be used: NRAO/AUI Archives, Walker Papers, <series/unit/subunit/box #>. Processing notes: Initial inventory of this collection was done in May by Walker. Final arrangement, description, indexing, foldering and boxing of this material was begun in July 2026 and is ongoing. During the processing, photocopies were made to replace thermofax sheets and newspaper clippings, fasteners were removed, and materials were removed from binders of various types. Duplicates were discarded. Very Long Baseline Interferometry (VLBI) Series: Related materials: For other materials on VLBI see the Records of the National Radio Astronomy Observatory, the Papers of Donald C. Backer, the Papers of Marshall H. Cohen, and the Papers of Kenneth I. Kellermann.
Very Long Baseline Array (VLBA) Series: The Very Long Baseline Array consists of ten, 240-ton, 25-meter diameter dish antennas spread across the Western Hemisphere, from Hawaii to St. Croix, Virgin Islands; it is a facility of National Radio Astronomy Observatory. Construction began in February, 1986, and was completed in May, 1993. This series includes materials on the history, development, and construction of the VLBA. Related materials: For other materials on the VLBA see the Records of the National Radio Astronomy Observatory, the Papers of Marshall H. Cohen, the Papers of Kenneth I. Kellermann and the Papers of Paul A. Vanden Bout.
Domenici Science Operations Center (DSOC) Series: Following the decision to locate the management and operation of the VLBA in Socorro, plans rapidly moved forward to build a facility for NRAO VLA and VLBA operations on the campus of New Mexico Tech in Socorro. Walker was a member of the NRAO committee working with the architect. The preliminary name for the facility was Center for Radio Astronomical Imaging; it was dedicated as the Array Operations Center (AOC) in December 1988, and was rededicated as the Pete V. Domenici Science Operations Center (DSOC) in May 2008. Material includes memos, reports, and diagrams dated 1985-1990. Size: 0.25 linear feet. Click here for a folder listing. |