On-chip signal processing to overcome IR detector nonuniformities

The interest in the nonuniformities in response of infrared detectors has increased recently due to the increased number of detectors being considered for future infrared sensors. This paper identifies how large a uniformity problem exists for various types of detectors and indicates the possible causes of the observed variation. Detector nonuniformity and present on-chip correction techniques can be considered within the two categories of scanning and staring systems. They are discussed separately since applicable correction techniques either need to be developed or are different. A survey is made of the nonuniformities encountered in the fabrication of detector arrays of photoconductive (PC) HgCdTe, PC PbS, PC Si:In and photovoltaic (PV) InSb. A discussion is not made of the use of calibration data stored in system signal processing memory because this straightforward approach will probably be located off focal plane.