METHOD MEASURING ABSOLUTE SPEED OF MOVEMENT OF UNDERWATER OBJECT AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2000 - IPC

FIELD: underwater acoustics. SUBSTANCE: polyharmonic signal is emitted by phased array according to proposed method measuring absolute speed of movement of underwater object. This signal has N frequency components forming fn uniformly distributed in octave range with upper frequency , where c is velocity of sound in water, in two symmetric angular sectors α = ±(30-90)^° along directions with reference to vertical line. Acoustic signal with frequencies f+n

, f_n reflected from bottom is received along each of 2N directions. Then Doppler frequencies are measured separately by each direction. After it absolute speed of movement of underwater object is computed. Device to measure absolute speed of underwater object includes converter of phased array made of case with internal space that houses restoring spring, two round piezoelectric plates, current-conducting plate. Frontal surface of one plate carries sealing layer. Device has excitation generator, antenna switches, transformers, preamplifiers, synchronous detectors, beam splitter, Doppler frequency meter and meter of absolute speed of movement of object. EFFECT: decreased error of measurement of momentary value of speed of movement of underwater object. 3 cl, 6 dwg