This shows the alignment of HST Guide Stars with a test image after a world coordinate system has been fit. The coordinates plotted are based on header keywords describing a plane-tangent system fit by matching HST Guide stars and sources found in the image.

[Image] [Image with Nominal WCS] [ID] [Image with Fit WCS] [ID]

[Image Map]

Open circles with 5 arcsecond radii represent the positions of stellar objects and X's with 5 arcsecond arms represent the positions of nonstellar objects in that catalog. They are also identified with their region and number. The dots are sources in the image.