Our initial studies show that these properties vary a great deal from plate to plate. Therefore, detailed analysis of individual plate characteristics is a prerequisite to carrying out accurate multiple-plate analysis of GSC objects. To determine the likelihood of an object of magnitude M appearing on a given plate, we compute the luminosity function for the plate, calculating limiting magnitude, saturation magnitude, and maximal population magnitude. The tendencies are computed using an iterative process. Initial studies demonstrate that tendencies of the majority of plates are a very significant factor in GSC classifications.
Solid line is smoothed data, dashed line is the best fit.
To determine whether some plates bias magnitudes, for overlapping plates we compute the mean magnitude discrepancy among objects that appear on both plates. To determine whether an object's classification is biased if the object is near a plate edge, we calculate the average density of objects of both classes as a function of distance from the plate center. To determine whether GSC plate quality codes are meaningful, we look for a correlation between plate quality codes and the parameters mentioned above. A number of problems can be traced to the plate-related effects discussed above. OM is grateful to the Russian Foundation for Fundamental Researches for grant No. 16304.