Title :
Up-the-ramp processing and cosmic ray rejection with limited memory
Author :
Fixsen, Dale I. ; Offenberg, Joel D.
Author_Institution :
Sci. Syst. & Applications Inc., NASA Goddard Space Flight Center, Greenbelt, MD, USA
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.
Keywords :
astronomical techniques; computational complexity; cosmic ray interactions; image sampling; nondestructive readout; optical noise; parameter estimation; Fowler processed data; Fowler sampled data; astronomical images; computer memory requirements; cosmic ray hit removal; cosmic ray rejection; large-area pixelized detectors; nondestructive readout; nonideal detector performance; optimal cosmic ray glitch rejection; optimal processing; pixel optimum noise estimate; pixel optimum signal estimate; processing time; uniformly sampled array image data; up-the-ramp processing; Compression algorithms; Computer buffers; Contamination; Cosmic rays; Costs; Detectors; Noise robustness; Sampling methods; Signal to noise ratio; Telescopes;
Conference_Titel :
Aerospace Conference Proceedings, 2002. IEEE
Print_ISBN :
0-7803-7231-X
DOI :
10.1109/AERO.2002.1035372