Abstract: Detecting the vehicles via acoustic and vibration signals has been widely used in battlefield surveillance, security, and anti-terrorism. A new method based on the features and similarity of signal envelops is proposed and applied in vehicle detection. The envelop delay-and-sum is used not only to improve the detection efficiency of moving vehicle, but also provides the direction and speed of its movement. The analysis of experimental data shows that all vehicles could be detected except for several vehicles passing through at the same time. Compared with the detected results from a single sensor in signal-noise-ratio and signal duration, the false alarm rate is decreased from 61% to 0%，while the missed detection rate is increased from 7.8% to 12.5%.

Key words: ordnance science and technology, vehicle detection, linear sensor array, envelop delay-and-sum, velocity estimation