PROCEDURE TO OBTAIN INFORMATION ON NOISY OBJECTS IN SEA Russian patent published in 2003 - IPC

FIELD: underwater acoustics, listening systems. SUBSTANCE: in compliance with procedure for obtainment of information on noisy objects in sea noise emitted by moving objects is received by antenna in at least three spatial channels of observation of signal arriving at different angles because of vertical refraction of sound. Received noise signal is digitized in time and is quantized in several levels, sound velocity in water is measured depending on depth and roughness of sea surface. Signal of object is calculated in each spatial channel for several values of range by solving equation of hydroacoustics under passive mode by measured data and known characteristics of bottom and receiving system. Decision on range, speed and presence of several noisy objects in one direction is made as result of comparison of measured values of signal with calculated values. Number of objects is estimated by number of steps showing such coincidence and speed is assumed equal to relation of length of step in range to digitization interval in time. EFFECT: potential for simultaneous determination of range and radial speed of objects moving in sea and found in one direction and determination of number of these objects. 1 dwg