NSFCAM2 Plate Scale Measurement
Feb 2013 Update
Because we installed a new array into NSFCam, we re-measured the plate scale. Once again, we observed an asteroid (in this case, 65 Cybele) passing close to a field star. By comparing the motion of the asteroid relative to the star in the images with the motion of the astroid on the sky based on its ephemeris, a very accurate measure of the plate scale can be had. The plate scale was measured to be 0.03973 arcseconds per pixel, with an uncertainty of 0.00002 arcseconds per pixel.