Range Gated Underwater Viewing

The major range limitation of artificially illuminated underwater television viewing systems is backscattered illuminant. For more than twenty-five years, experiments have been conducted to perform range-gating to defeat backscatter. Currently available off-the-shelf hardware makes the implementation of range-gated viewing much more practical than it was previously. This paper analyzes requisite system parameters and describes a developmental system employing a doubled Nd-YAG laser and a gated Intensified Charge Coupled Device (ICCD) camera.