Abstract: An event detection and classification system uses a new type of optical sensing component, a Position Sensing Detector Focal Plane Array (PSD-FPA). The PSD-FPA provides for high-speed operation that allows for accurate sensing of fast artifacts that are unique to weapons fire and enables precise location of optical phenomenon. The system detects and classifies events, particularly weapons fire, and rejects false alarms. An optical lens sub-system focuses light onto a PSD-FPA, which senses the photons and generates electrical signals associated with individual elements of the PSD-FPA. These signals are processed to identify and classify weapons-related or other events. Background subtraction, variable gain, time-intensity and time-location correlation, digital filtering, Fourier analysis, and wavelet analysis are all used to successfully classify the events while rejecting false alarms.

Abstract: A Sensor Chip Assembly (SCA) contains a focal plane array constructed as a semiconductor chip sandwich. One slice contains an array of PSDs made from IR sensitive semiconductor material, and the other slice contains Trans Impedance Amplifiers (TIAs)—and associated on-chip signal processing elements from an electronic semiconductor material. The SCA resembles those made for pixelized imaging IR SCA focal planes, but the configuration and implementation of which is for a PSD focal plane array. The use of these techniques assures that the PSD focal plane array possesses the required attributes. Interconnect technology is widely available from most IR fabrication houses to connect the IR array with the TIA circuits.