title: Modulated pulse laser with pseudorandom coding capabilities for underwater ranging, detection, and imaging.
abstract: Optical detection, ranging, and imaging of targets in turbid water is complicated by absorption and scattering. It has been shown that using a pulsed laser source with a range-gated receiver or an intensity modulated source with a coherent RF receiver can improve target contrast in turbid water. A blended approach using a modulated-pulse waveform has been previously suggested as a way to further improve target contrast. However only recently has a rugged and reliable laser source been developed that is capable of synthesizing such a waveform so that the effect of the underwater environment on the propagation of a modulated pulse can be studied. In this paper, we outline the motivation for the modulated-pulse (MP) concept, and experimentally evaluate different MP waveforms: single-tone MP and pseudorandom coded MP sequences.
authors: Naval Air Systems Command, Patuxent River, Maryland 20670, USA. brandon.cochenour@navy.mil
authors: Brandon
authors: B
authors: Cochenour
authors: Linda
authors: L
authors: Mullen
authors: John
authors: J
authors: Muth