Off line-of-sight measurements of target vibrational features using laser vibrometry

Laser vibrometry based on coherent detection techniques allows remote measuring of vibrational target characteristics with high resolution. Previous work concentrated on measurements where a direct line-of-sight between target and sensor was given. In this paper we investigate situations where the target is hidden and out-of-sight, but target-induced vibrations can be captured from the environment or via indirect viewing. This approach opens up new areas of application in the field of defence and security. The presented measurements were performed with an in-house-developed all fiber-based 1.5 ?m laser radar named SAVIS (Short Wave Active VIbration Sensor).