Field and Laboratory Boresighting Methods for Hyperspectral Imaging Sensor Systems

Multi-sensor platforms for airborne reconnaissance and surveillance often require the alignment of two or more imaging systems along a common optical axis. This is true especially when data fusion is performed where the signal processing involves the analysis of data taken from different sensors at the same time and of the same location. For example, the NRL War Horse platform combines imagery from a VIS/NIR slit-dispersive hyperspectral sensor with imagery from a slit-aperture linear CCD array camera with pointing and geolocation information from a digital GPS/INS instrument (C-MIGITS). This sensor suite has flown successfully aboard the Unmanned Air Vehicle (UAV) Predator. Several crude boresighting procedures have been adopted for use in the field which take advantage of long baselines between the camera systems and objects at a distance. However, accurate alignment procedures are difficult to perform in the field owing to variable and unpredictable hangar, aircraft, and weather conditions. Typically, the various imaging and geolocation instruments are mounted on mechanical frame prior to installation on the aircraft. Hence, it is desirable to have an accurate method for boresighting a suite of sensors to a common optical axis in the laboratory using a relatively short baseline. The original document contains color images. All DTIC reproductions will be in black and white. Prepared in collaboration with SFA Inc., Largo, MD.