Depth fingerprint map of active range-gated imaging for real-time three-dimensional measurement of foreground objects.

We present a depth fingerprint map to obtain three-dimensional (3D) spatial information from objects in a large deterministic background by active range-gated imaging, for night remote surveillance. This method first gives the depth fingerprint map of the region of interest in the background by gate viewing in the form of contour bands in range. The map is then embedded in the range-gated laser surveillance system. Finally, 3D spatial information such as target scale and location can be estimated by segmenting the target from the background and matching them with the depth fingerprint map. The measurement is performed by computer background processing. Therefore, the method has no influence on the frame rate of surveillance systems and can realize real-time surveillance. In this paper, the approach to acquisition of the depth fingerprint map is also demonstrated without an echo-broadening effect.