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Changes between Initial Version and Version 1 of STS.2010.astrometry

v1	v1
	1	Due to the errors in astrometry caused by the bright star effect we need to reprocess the STS observations from 2010. A first pass using the recipe developed by Gene STS_DATASET does noticibly improve the results, but not to an acceptable level.
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	3	After some iterations we may have come up with a set of recipe values that generate better results from the troublesome chips for stars other than the bright ones.
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	5	Examining plots of dRA versus instrumental magnitude we find that the bright star effect occurs for stars brighter than -12. At around -11 the errors start to increase significantly. If we restrict the astrometric fit to use stars between -12 and -11 we get better results. The attached image is a montage of plots of dRA versus instrumental magnitude for exposure o5426g0113o. ota 76 is at the upper left and ota 01 is on the lower right.