The StarScan Plate Measuring Machine: Overview and Calibrations
Abstract
The StarScan machine at the U.S. Naval Observatory (USNO) completed measuring photographic astrograph plates to allow determination of proper motions for the USNO CCD Astrograph Catalog (UCAC) program. All applicable 1940 AGK2 plates about 2200 Hamburg Zone Astrograph plates, 900 Black Birch (USNO Twin Astrograph) plates, and 300 Lick Astrograph plates have been measured. StarScan comprises a CCD camera, a telecentric lens, an air-bearing granite table, stepper motor screws, and Heidenhain scales to operate in a step-stare mode. The repeatability of StarScan measures is about 0.2 microns. The CCD mapping as well as the global table coordinate system has been calibrated using a special dot calibration plate and the overall accuracy of StarScan x, y data is derived to be 0.5 microns.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 28, 2008
- Accession Number
- ADA482702
Entities
People
- E. R. Holdenried
- G. L. Wycoff
- J. P. De Cuyper
- L. Winter
- Norbert Zacharias
- T. J. Rafferty
Organizations
- United States Naval Observatory