Novel architecture for a hybrid acoustic-radar buried-object detection system

We have created a new architecture for the detection and location of specific buried targets. The system uses a combination of acoustic vibrations and electromagnetic waves to achieve highly specific target recognition, and a multistatic configuration to determine target location. The mechanical vibration resonance properties of the constituent elements of the targets constitute a signature which can be identified in clutter. In order to better detect these vibrations, continuous-wave radar signals are used rather than acoustic reflections, as in sonar-based systems. The energy stored in resonant vibrating elements is not directly detected, but rather modulates the radar signal. The received signals are sampled at high resolution to facilitate target signature recognition by cross-correlation and phase measurement. Location is accomplished by travel time determination for each receiver using absolute phase measurements at multiple frequencies. The phase measurements provide multiple sets of confocal elliptical lines of position, whose intersection identifies the target location. The region in which a mine can be precisely located is a subset of the region in which its presence can be detected