Abstract: An inertial navigation system (INS) and a monopulse radar system are mounted on a body. The inertial navigation system outputs at least a velocity of the body. Either a synthetic aperture radar (SAR) map or doppler beam sharpening (DBS) map is created using the outputs of the monopulse radar system. The monopulse radar system outputs at least a summation output, an azimuth difference and an elevation difference associated with an object detected in either the SAR or DBS map. The position processor of the system and method of the present invention, however, only inputs the summation output and one of the azimuth difference and election difference. The position processor determines the other of the azimuth difference and the elevation difference by converting the velocity output by the INS into a doppler angle .theta. (the angle between the velocity, a vector, and a line connecting the object and the body) and determining either the azimuth difference or the elevation difference from the doppler angle .theta..

Abstract: An underwater transducer which includes a fluid circuit having a valve disposed in a plenum chamber having a small aperture open to the ambient water pressure. Fluid flow into and out of the chamber by way of the valve is governed by controlling the valve opening and closing in accordance with movement of an electrodynamic driver which receives an input signal to be transmitted.