This volume constitutes the proceedings of the Thirteenth Inter national Symposium on Acoustical Imaging which was held in Minneapolis, Minnesota during October 26-28, 1983. Forty-eight research papers were presented during the meeting by researchers from twelve countries, again demonstrating the true international character of these meetings. Of these presentations this volume contains forty-two complete manuscripts. The abstracts for addi tional papers that were not available at publication time are also included. According to the recent tradition of these symposia an inter disciplinary...