Understanding and mitigation of false alarms as measured in LWIR clutter by the AIRMS sensor

摘要

A key issue for an IRST is the occurrence of false alarms, especially against a structured background. This paper reviews observations of false target detections and mitigation techniques on a variety of scenes obtained by the AIRMS sensor (Airborne IR Measurement System). A collection of scenes with cloud and terrain clutter backgrounds of various types and ranges were processed. The processing stream consisted of a combination of space-time filtering, including scene registration, in order to optimally remove clutter. For scenes with appreciable clutter background, the dominant source of false alarms is clutter leakage due to imperfect subtraction of the clutter. An approach to false alarm mitigation based on a first principles understanding of the causes of leakage was applied to the scenes with favorable results. The technique was able to reduce the impact of the false alarms. By comparing the technique to the conventional method of background normalization a further improvement was observed. The technique shows great potential for obtaining the low false alarm rates required for today's IRST scenarios.