Sensor modeling using a universal programmable interface for hardware-in-the-loop IR/EO testing

A Universal Programmable Interface (UPI) has been developed by Amherst Systems, under contract to the Air Force Flight Test Center (AFFTC) at Edwards AFB, with additional funding support from the Naval Air Warfare Center (NAWC/AD) at Patuxent River, MD, to provide a configurable interface for hardware-in-the-loop (HWIL) testing of infrared and electrooptical (IR/EO) sensor systems. The UPI supports the interface between a scene generation system (SGS) and the unit under test (UUT) through either direct injection of the signals into the system's processing electronics or the projection of in-band scene radiance into the sensor's optical aperture. To properly stimulate the UUT, the UPI must simulate various sensor effects, emulate by-passed sensor components and reformat the data for direct injection or optical projection. This paper will discuss the sensor modeling capabilities of the UPI and the supporting software and hardware. Sensor modeling capabilities include image blurring due to the sensor's modulation transfer function (MTF) and pixel effects. A sensor modeling and analysis software tool, based on FLIR92(1) will be discussed. A technique for modeling other sensor effects will also be presented. This technique, called pixel displacement processing, can model geometric distortion, physical sensor jitter, and other user specified effects. It can also be used to accurately perform latency compensation.