| 摘要 |
PURPOSE:To display definitely the shape of a target and to display exactly the attitude of the target, by adding a phase fitting circuit which approximates the target deviation angle determined from the phase characteristics of the output from a mutual correlation circuit by a linear expression, a spread calculation circuit which calculates the spread in an azimuth direction from the approximate value, and an amplitude superposition circuit which superposes the amplitude of the output from the mutual correlation circuit on the spread in the azimuth direction and displays the same. CONSTITUTION:The acoustic wave from a target is converted to an electrical signal by an acousto-electric conversion section 1, and the electrical signal is fed to a preamplifier circuit and an analog-digital (A/D) conversion circuit 2, by which the signal is converted to a digital signal. The digitized reception signal forms each two of right and left reception beams having respectively the equal characteristics with respect to one azimuth in a phase matching circuit 3. The beams are fed through a filter circuit 4 to a mutual correlation calculation circuit 5. The amplitude of the correction output and the phase difference between the right and left beam outputs which are the outputs of the circuit 5 are once stored in a storage circuit 6, and are then fed to a phase fitting circuit 7. The deviation angle of the target from the phase of the mutual correlation is approximated by a linear expression in the circuit 7. |
