Rapid unambiguous signal analysis of the electromagnetic spectrum by tactical ESM and ECM systems has become progressively more challenging due to the proliferation of high duty cycle radars which produce multiple simultaneous signals at the target platform. Severe problems arise when the band-of-interest contains a large number of signals of different amplitudes and types of modulation; the difficulties are compounded if the signals are pulses of relatively short duration. Most of the threat parameters used for sorting can now be changed on a pulse-by-pulse basis and the frequency of a signal may even be shifted or spread within a pulse. This Phase I effort addresses the development of a receiver which has an enhanced capability for measuring the frequency in high signal density environments in addition to the other key parameters (PW, PRI, and potentially AOA) that significantly upgrade overall system performance. Acousto-optic-based channelized receiver technology is a prime candidate for consideration. The major advantage of threat analysis using acousto-optic Bragg diffraction is the inherent capability for wideband spectrum analysis on a real-time, wide-open basis with good frequency resolution. The proposed effort will examine candidate AO-based architectures and develop a demonstration breadboard.