Up-the-ramp processing and cosmic ray rejection with limited memory

Abstract

The optimal rejection of cosmic ray glitches from astronomical images is of critical importance for large-area pixelized detectors in space. We present an algorithm for optimally processing uniformly sampled array image data obtained with a nondestructive readout. The algorithm discards full wells, removes cosmic ray (particle) hits and other glitches, and makes a nearly optimum estimate of the signal and noise on each pixel. The computer requirements, including memory, are modest, and the results are robust. The results are shown and compared to results of Fowler sampled and processed data. Non-ideal detector performance may require some additional code, but this is not expected to cost much processing time.