1. Create seamless mosaics from the many images taken on each night
2. Measure the location and brightness of all the "stars" in every mosaic (it's okay if some galaxies creep into the sample, since they won't show any motion)
3. Match the detections of stars observed on different nights, so that we have a list of the position of each star over time

                Date        Julian Date        row     column
             2002 Nov  1    2,452,579.9      4587.42   2394.55
             2002 Nov  2    2,452,580.9      4587.45   2394.54
             2002 Nov  9    2,452,587.8      4587.43   2394.55
             2003 Sep 22    2,452,905.0      4587.49   2394.52
               ...
        

4. Calculate the proper motion of each star, together with an uncertainty in the motion
5. Select a sample of stars which show significant motion for further study

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