An automated astronomical image processor

The design of an automatic image processing system which is based on an AMD-1 microdensitometer is described. The system contains an optical section with a dual-beam design, a measurement unit, and a calibration unit. The measurement unit is composed of illuminating and projection microscopes, illumination and measurement diaphragms, and a photodetector, and the calibration unit has a light guide and a reference photodetector. The image scanning, which is conducted with a two-coordinate mechanically controlled sweep, is examined. The system is also capable of reproducing extracted halftone information on photographic film. The system has a photometric accuracy of 1-2 percent, positional accuracy of 5 microns, and an optical density range of 0-4 D. The potential error factors which include scattering with the optics, nonlinearity, drift, and the operation speed of the electronic photometry channel are analyzed. The image processing system is applied to stellar spectra and the optical identification of radio sources.