| 摘要 |
PROBLEM TO BE SOLVED: To provide synthetic aperture sonar that can be used in an actual sea area, without requiring known targets, acoustic marks, etc., and can take movement such as yawing of a platform into account. SOLUTION: A correlation calculating section a22 calculates the phase difference between signals range-compressed by means of range-compressing sections a19 and b20, by correlating the signals with each other, and another correlation calculating section c23 calculates the phase difference between signals range-compressed by means of range-compressing sections c21 and b20, by correlating the signals with each other. Oscillation estimating sections a24 and c25 estimate the amount of oscillation from the information on the phase differences calculated by the calculating sections a22 and c23 and on the information on yawing etc., from a gyroscope 30. An oscillation correcting section 26 corrects received signals, based on the estimated amount of oscillation, and a range curvature correcting section 27 corrects short-distance sound field effects with respect to pixels on an image, based on the corrected result of the correcting section 26. In addition, an azimuth compressing section 28 correlates the corrected pixels with a precalculated reference signal. COPYRIGHT: (C)2004,JPO
|
