1. A method for dynamically changing a target detection system parameter, comprising: receiving image data, output from a sensor in a receiving system and generated using one of a discrete set of sensor integration times wherein each integration time being associated with a corresponding temperature range; determining whether said image data satisfies at least one predetermined threshold; and selecting the same one or a different sensor integration time for a succeeding frame of image data to produce a predetermined sensor sensitivity based on said image data satisfying said at least one predetermined threshold.