NEW FALSE ALARM REDUCTION TECHNIQUES FOR IRMWS

The classical methods for rejecting false targets in airborne infrared missile warning sytems, include spatial, spectral, temporal and angle tracking techniques, have been explored on numerous development programs are currently inherent in operational IR missile warning systems such as the AN/AAR-44. However, flight tests have shown that there are still a number of ground sources that will create false alarms in the sytem. Furthermore, the use of amplitude growth in target signal has not proven to be reliable method of determining if the detected source is an approaching missle. The proposed effort will evaluate the use of a class of unique spatio tempora algorithms called Optical Flow to distinguish real threats from false alarms. It takes advantage of the difference in characteristics between a source that is moving in the MWS field of view as the aircraft flies toward it and a missile that is approaching the aircraft at a much faster rate than the ground source. The OFA algorithm proposed will also take advantage of the chagnes in range and range rate of the missile and not rely on the change in amplitude as the potential threat approaches. The proposed program will evaluate the OFA on a UNIX workstation using the data recorded during the flight test of the SNJW IR MWS testbed. This testbed employs a Galileo 256x 256 insb digital sensor and provides a credible model for future IR MWS sensors using 2DFPAs. Should the OFA technique prove effective against current data, it is proposed in Phase II to conduct field and flight trials using the SNJW testbed. This will result in a live fire test plan to be implemented in Phase III. Since this sensor may be integrated into the LIFE laser IRCM program, the successful implementation of the OFA will also benefit that program. The purpose of Phase III will be to develop a preproduction model of an IR MWS employing the OFA, that has the resolution and sensitivity needed to detect modern threats at ranges sufficient for engagement by a direct energy countermeasures system such as that being developed on the LIFE program.