This paper proposes a new method in sonar signal processing using ”Overlappingsectional synthetic aperture.” This method is developed to provide high azimuth resolution in a synthetic aperture operation evenwhena ship cannotkeepmoving on a straightbaseline.Theaperture direc tion is at first detected with a gyroscope and made parallel to the base line using mechanical feed back system. Signals from the overlapping part of two successive apertures overlapping in the base line direction with the lateral deviation in position are compared and the phase difference between two signals is detected. Signal of non-overlapping part of the second aperture is corrected using thisphase difference. It is possible to obtain much higher azimuth resolution thana realaperture by repeating this procedure. This method does not require to change most of conventional sonar sys tem and the signal processing is performed mostly using Fourier transform. Results of computer simulation prove the effectiveness of this method.
