Ground Penetrating MIMO Vibrometer

Vadum will develop a Ground Penetrating MIMO Vibrometer (GPMV) which utilizes a radio-acoustic Multiple Input Multiple Output (MIMO) aperture to detect surface and buried explosive hazards. The sensor leverages common hardware to achieve three distinct modes of operation using low and high frequency bands for both the Acoustic Frequency (AF) in the acoustic transmitter and the Radio Frequency (RF) in the RF transceiver. The modes of operation are: 1) a low-RF low-AF mode to detect the vibrational response of buried targets, 2) a high-RF low-AF mode to detect the disturbed earth above buried targets, and 3) a high-AF mode to image surface targets in clutter environments unsuitable for traditional forward-looking radars. The MIMO aperture enables beam focusing, spatial filtering, and image formation without the requirement for vehicle motion as in Synthetic Aperture Radars (SAR). The dynamic range of the GPMV is maximized using an active feed-forward analog canceller, which provides the added benefit of measuring the amplitude and phase response in the GPMVs field of view. This additional sensing modality can affectively be used to sense dielectric discontinuities which indicate the presence of a buried hazard. The Frequency Modulated Continuous Wave (FMCW) acoustic stimulus and beamforming techniques provide information about target range, size, and shape. Analysis of the baseband waveforms can be used to classify targets based on shape.