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.