Target detection system utilizing multiple optical criteria

摘要

A laser-based target detection system applicable for search-and-rescue type operations takes into account a plurality of optical attributes in the energy delivered to, and received from, a target-containing area so as to enhance effectiveness. In addition to analyzing the returned optical signature for sufficient energy reflected by a potential target at a primary laser wavelength, the system also senses the target's effect on a supplemental optical attribute, and only when sufficient amplitude at the primary wavelength is detected in conjunction with a substantial effect on the supplemental optical attribute is a valid target confirmed. In one embodiment, the supplemental optical attribute is amplitude at a wavelength other than the primary wavelength, with the system preferably looking for a high degree of attenuation at the non-primary wavelength. In an alternative embodiment, polarization is used as the supplemental optical attribute, with the system preferably looking for change of orientation in the return optical signature.