ERROR ANALYSIS OF FULL-FIELD ASTROMETRY WITH A SCHMIDT TELESCOPE

Positional errors after a full-field plate solution were analyzed for plates taken by the 105-cm Kiso Schmidt telescope with an emphasis placed on the plate-constant error. From two sets of plates, one of which comprised nine plates for five consecutive nights, the mean random plate error was estimated to be 0.''12-0.''15. By regarding each one of the reference stars on a plate as being an object star, the error distribution for object stars could be simulated. The error for object stars is shown to sometimes be a few times larger than the standard deviation of the residuals for the reference stars, especially for star numbers of less than about 50;. this phenomenon is suggested to be due to error propagation inherent in the least-squares procedure. This error amplification/attenuation mechanism could be explained using a simple numerical simulation. The amounts of other error components are discussed using ZZCAT catalog.