Acoustic Imaging Using a 3 MHz Thin Lens System

This research was performed by Bruce Johnson of the Naval EOD Technology Division. Image postprocessing was done in part by Kevin Fink working under Dr. Ed Belcher of the Applied Physics Laboratory, University of Washington.

Cylinder B lying on sandy bottom of test tank.

The cylinder was at a 30 degree angle from the plane of movement of the sonar. The closed end of the cylinder and a pattern of 6 bolt heads can be seen in the image.

Cylinder A lying on sandy bottom of test tank - View 1

Cylinder lying on sandy bottom of test tank - View 2

The cylinder was parallel to the plane of movement of the sonar. The bright stripe across the cylinder is the line of normal incidence. Two patterns of 6 bolt heads and a metal fin can be seen in the images.