| 摘要 |
PROBLEM TO BE SOLVED: To improve the accuracy of phasing azimuth without enlarging the memory size by specifying the phasing azimuth velocity-corrected with a delay time calculation means and then calculating phasing compensation quantity at using frequency corresponding to the azimuth. SOLUTION: A delay time calculation means 10 calculates a delay timeτip from a distance difference Dip between a using sensor at every divided azimuth contained in a distance difference memory means 11 and a phasing base and sound velocity information Cf and is stored in a memory. A delay time selection means 9 selects the delay timeτip according to the phasing azimuth informationθfrom the delay timeτip and a delay time calculation means 8 calculates a delay phaseψip(f) using the delay timeτip and a specific frequency f. A phase compensation calculation means 5 input by this calculates a phase compensation quantityϕip(f) to output to a phasing means 3. In this manner, by correcting the sound velocity with the delay time calculation means and calculating the phase correction quantity at the frequency used for phasing according to the specified phasing azimuth, the azimuth accuracy of phasing is improved without enlarging the memory size.
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