This paper consists of two parts.
Part I is concerned with studying a high-resolution, underwater imaging method using the theory of synthetic aperture radar. The range resolution can be increased the use of linear FM and the azimuth resolution through matched filtering of Doppler shift signal caused by the relative motion of the sonar and the object. The performance of the designed system was confirmed through computer simulation and the feasibility of the synthetic aperture sonar was shown by an experimental setup.
Part II of the paper presents a method of simulating the pulse-echo pattern of an arbitrary-shaped ultrasonic transducer reflected from a line object. The simulation results agreed with the experimental results better than the conventional method assuming a point source. The proposed method was applied to investigate the characteristics of a linear array transducer.
