Remote audio/video acquisition for human signature detection

To address the challenges of noncooperative, large-distance human signature detection, we present a novel multimodal remote audio/video acquisition system. The system mainly consists of a laser Doppler virbometer (LDV) and a pan-tilt-zoom (PTZ) camera. The LDV is a unique remote hearing sensor that uses the principle of laser interferometry. However, it needs an appropriate surface to modulate the speech of a human subject and reflect the laser beam to the LDV receiver. The manual operation to turn the laser beam onto a target is very difficult at a distance of more than 20 meters. Therefore, the PTZ camera is used to capture the video of the human subject, track the subject when he/she moves, and analyze the image to get a good reflection surface for LDV measurements in real-time. Experiments show that the integration of those two sensory components is ideal for multimodal human signature detection at a large distance.