Active imaging system: a long range scanned laser

A long range imaging system using a scanned Nd-YAG laser beam with high average power for target illumination is described. Distance measurements can be performed with an accuracy defined by the rise time of the laser pulses. The contrast is enhanced by suppression of the atmospheric backscatter, and time varying gain amplifiers are used to reduce the dynamic range requirements at the display side of the system. Parts of the target scene can be extracted by gating the electrical signal. A new technique is described whereby three-dimensional images are obtained by range dependent corrections on the horizontal deflection of the display electron beam.