Experimental investigation of buried landmine detection using time division multiplexing of multi-beam laser Doppler vibrometer channels

Producing vibration images of buried landmines using a multi-beam laser Doppler vibrometer (MB-LDV) operating from a stationary platform have been accomplished in the past. Detection from a continuously moving platform can reduce the time of detection compared to stop-and-stare measurement. However, there is a speed limitation, imposed by the required spatial and frequency resolution. NCPA proposed a concept of time division multiplexing (TDM) of laser beams of a MB-LDV to overcome that speed limitation. The system, based on 16-beam MB-LDV, has been built and experimentally tested at an Army test facility. Vibration velocity profiles of buried mines have been obtained at different system speeds. Algorithms for speckle noise reduction in continuously moving MB-LDV signals have been developed and explored. The results of the current data collection, recent past data collection as well as the results of the effectiveness of speckle noise reduction techniques are presented.