Detector integration time issues associated with FLIR performance

IR detector integration time is determined by a combination of the scene or target radiance, the noise of the sensor, and the sensor sensitivity. Typical LWIR detectors such as those used in most U.S. military systems can operate effectively with integration times in the microsecond region. MWIR detectors require much longer integration times (up to several milliseconds) under some conditions to achieve good Noise Equivalent Temperature Difference (NETD). Emerging 3 ^rd Generation FLIR systems incorporate both MWIR and LWIR detectors. The category of sensors know as uncooled LWIR require thermal time constants, similar to integration time, in the millisecond range to achieve acceptable good NETD. These longer integration times and time constants would not limit performance in a purely static environment, but target or sensor motion can induce blurring under some circumstances. A variety of tasks and mission scenarios were analyzed to determine the integration time requirements for combinations of sensor platform movement and look angle. These were then compared to the typical integration times for MWIR and LWIR detectors to establish the suitability of each band for the functions considered.