FACETED HEMISPHERICAL LASER DETECTOR WITH HIGH DIRECTIONAL RESOLUTION

THE PROGRAM MISSION IS TO PROVIDE AN ON-BOARD SATELLITE WARNING SYSTEM, CAPABLE OF DETECTING AND LOCATING VIRTUALLY ANY INCOMING LASER BEAM. OUR APPROACH HAS BEEN TO BUILD A SEGMENTED HEMISPHERICAL DETECTOR INCORPORATING KEY FEATURES FROM THE DESIGN OF AN INSECTS'S EYE. THE HEMISPHERE IS APPROXIMATELY EIGHT INCHES IN DIAMETER, WEIGHING LESS THAN FOUR POUNDS. THE SURFLACE HAS DIRECTIONAL HOLES THROUGH WHICH THE INDIVIDUAL SENSORS LOOK. THESE DETECTORS ARE SPACED AT ANGULAR INTERVALS SUCH THAT ANY DISTANT POINT OF LIGHT IS OBSERVED BY SEVERAL NEIGHBORING DETECTORS. A SIMPLE CENTROID ALGORITHM CALCULATES THE DIRECTION OF THE SOURCE TO AN ACCURACY OF BETTER THAN ONE DEGREE IN SOLID ANGLE FROM THE OBSERVED DISTRIBUTION OF SIGNAL INTENSITIES THE ANGULAR DETECTOR ARRAY IS SUPPLEMENTED WITH A SET OF DETECTOR CLUSTERS WHICH ANALYZE THE FREQUENCY SPECTRUM AND THE TEMPORAL VARIATIONS IN LIGHT INTENSITY. INFORMATION FROMTHE CLUSTERS IS USED TO RECOGNIZE THE ONSET OF MONOCHROMATICLIGHT. THIS APPROACH LEADS TO A SIMPLE, RUGGED, NON-IMAGINGDETECTOR CAPABLE OF RECOGNIZING AND LOCATING A LASER THREAT IN LESS THAN ONE MILLISECOND. VIRTUALLY ALL COMPETING TECHNOLOGIES ARE BASED ON IMAGING OPTICS AND RELATED RECOGNITION HARDWARE AND SOFTWARE, MAKING THEM SLOWER, MORE COMPLEX, AND LESS VERSATILE.