A computer model of a high-resolution sector-scanning sonar used for imaging objects against the sea bottom is presented. The model accounts for the sonar parameters, bottom backscatter, reflections from the target's visible surface, and the target's acoustic shadow. A variety of imaging scenarios can be simulated including the type of target, the target's orientation relative to the sonar and the bottom, and the backscatter statistics. The acoustic images are presented in the conventional B-scan format. A new display format that is useful for visualizing the target's silhouette is also presented. Visual perspective images of the scene are presented to serve as a reference for subsequent image reconstruction work. Preliminary results for 3-d reconstruction of the confining volume of the visible target surface are also presented. The simulation model and the results of the 3-d reconstruction demonstrate the promise of the application of image processing techniques for classification of objects using acoustic images. (kr)