Abstract: A multibeam synthetic aperture sonar system that includes a sonar projector. The projector transmits a transmitted sonar signal. A multibeam sonar receiver receives a reflected sonar signal created by the reflection of the transmitted sonar signal off materials and objects ensonified by the transmitted sonar signal. The receiver generates an output signal representative of the reflected sonar signal. The synthetic aperture sonar processor receives the signal output from the multibeam sonar receiver and processes the signal with synthetic aperture algorithms.

Abstract: An underwater location system (16) is disclosed having a plurality of locator modules (18), each capable of finding the relative range and bearing of other modules. The modules may be diver mounted, placed on movable objects such as a boat (14) or on fixed positions such as the sea floor (12). Range and bearing to each module of the system is displayed, upon request, on a console (20) which may be hand held or mounted in a diver's instrument console. Each module can interrogate other modules with an acoustic pulse which is answered, after a unique time delay stored in each module, by an acoustic response pulse. Response pulse sources are identified by their arrival in a time detection window set by their unique time delay. Range to each identified transponder source is calculated from a receipt time within each detection window.

Abstract: A sensor for a hydro resistance anemometer is designed for immersion in a flowing fluid to provide flow velocity information. The sensor is of a cylindrical configuration with a hemispherical nose. A driving electrode extends axially along the sensor and is exposed to the flowing fluid only at the center of the hemispherical surface of the sensor nose. A reference electrode of annular cylindrical configuration is disposed coaxially about the driving electrode and separated therefrom by a dielectric insulating material. The power dissipated through the sensor is typically on the order of only ten milliwatts.