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Background/Introduction: Acoustic remote sensing is the primary means of target detection and observation within the ocean interior for undersea applications. Detection of undersea platforms via activ... Background/Introduction: Acoustic remote sensing is the primary means of target detection and observation within the ocean interior for undersea applications. Detection of undersea platforms via active and passive acoustics is becoming increasingly difficult due to advances in quiet propulsion, and surface treatments. Therefore, it is advantageous to be able to remotely sense the turbulent wake that is formed as the vehicle travels through the ocean. Under this CRUSER project, we request purchase of a broadband, high-frequency echosounder that is capable of being operated from both a small RHIB (boat) platform, as well as an unmanned underwater vehicle (UUV). We intend to use this instrument using both the NPS RHIB, as well as UUVs operated by the NPS Mechanical Engineering department, which are REMUS models manufactured by Hydroid Inc. Minimal Technical Requirements/Salient Characteristics: A broadband (also called wideband in the industry) acoustic echosounder system consisting of a transducer, transceiver, operating software, mounting hardware, and deck cables. These components must have the following features. Transducer requirements: -Center frequency of approximately 200 kHz -Bandwidth covering the 170 – 240 kHz range. -nominal 7-degree beamwidth at the center frequency -max depth of at least 200m. -transducer face split into 3 or four independent channels, so electrical phase and physical angle of point targets can be estimated Transceiver requirements: -capable of integration into UUV, specifically REMUS models. -Demonstrated history of integration into autonomous platforms (wave gliders, AUV, USVs etc.) -splash proof housing and connectors -ability to operate in preprogrammed, or autonomous mode. -Tapering of transmitted pulse to reduce ringing of transducers -consumes less than 5 W during active transmission. -3 or 4 channel input to accept split beam transducer, -transmits frequency modulated pulses, either preprogrammed, or waveforms created by end-user. Required to improve SNR. - Dimensions of device smaller than 13x6x6 cubic inches. -requires 12 Volts DC power supply. -ability to control pulse repetition rate and duration. -ability to obtain output in phase and quadrature raw data. This could either be from the A/D converter, or basebanded and decimated data derived from it. -ability to calibrate transducer and power amplifier to obtain scattering cross section (volume, or surface) from the environment.