A Ladar Cloud/Target Polarization Discrimination Technique

摘要

The use of laser detection and ranging (ladar) systems in the atmosphere is limited by the severe attenuation of the signal due to absorption by atmospheric gases and/or scattering by cloud and fog particles. Furthermore, the cloud and fog particles may scatter the transmitted radiation toward the receiver, thus producing a false return, which must be distinguished from the true target return. Described herein is an optical polarization technique for discriminating between a cloud return and a target return. Also presented are the results of a research program which demonstrated the validity of the discrimination technique both in the laboratory and in the field. The conclusion is that the cloud/target discrimination technique will greatly improve the capability of a ladar system to distinguish between an atmospheric cloud and a target. (Author)