The usefulness of a flying spot digitizer for the measurement of the coordinates of star images on photographic plates

The flying spot digitizer can measure the coordinates of star images on photographic plates in one pass with an accuracy of 4.8 microns r.m.s. error. A field of the size 50 x 100 square millimeters is measured in a few seconds. Suggestions are made as to how a better accuracy can be achieved through the way in which the measurements are arranged and by repetition of the measurements. It is suggested that the speed of photographic astrometric measurements can be improved by about two orders of magnitude, at no loss of accuracy, by proper use of the FSD.