In this paper, a new LIDAR based approach to underwater range imaging is presented and initial results are described. The approach is inspired from the recent developments in Time Correlated Single Photon Counting techniques (TCSPC) developed in air for kilometre range 3D imaging. The time-correlated single-photon counting technique is based on measuring the time difference between an optical input pulse, typically a repetitive short-pulse laser signal, and a photon event recorded by a single-photon detector. When a photon is detected, the timing difference between the corresponding laser pulse and the detection event is recorded and added to a timing histogram. Repeated over many pulses, the timing histogram builds a statistically accurate representation of the actual optical transient signal being measured, enabling range estimation. Since TCSPC technique requires that the probability of detecting a photon event for each laser pulse has to be much less than one, such an approach is ideal for measurements of fast (ie ps - ns), low-level light signals, which are typically found in underwater environments.
展开▼
