Overview of a hybrid underwater camera system
Philip M. Church, Weilin W. Hou, Georges R. Fournier, Fraser R. Dalgleish, D. Alex Butler, S. Neelavathy Pari, Michael Jamieson, David A. Pike · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2014
The paper provides an overview of a Hybrid Underwater Camera (HUC) system combining sonar with a range-gated laser camera system. The sonar is the BlueView P900-45, operating at 900kHz with a field of view of 45 degrees and ranging capability of 60m. The range-gated laser camera system is based on the third generation LUCIE (Laser Underwater Camera Image Enhancer) sensor originally developed by the Defence Research and Development Canada. LUCIE uses an eye-safe laser generating 1ns pulses at a wavelength of 532nm and at the rate of 25kHz. An intensified CCD camera operates with a gating mechanism synchronized with the laser pulse. The gate opens to let the camera capture photons from a given range of interest and can be set from a minimum delay of 5ns with increments of 200ps. The output of the sensor is a 30Hz video signal. Automatic ranging is achieved using a sonar altimeter. The BlueView sonar and LUCIE sensors are integrated with an underwater computer that controls the sensors parameters and displays the real-time data for the sonar and the laser camera. As an initial step for data integration, graphics overlays representing the laser camera field-of-view along with the gate position and width are overlaid on the sonar display. The HUC system can be manually handled by a diver and can also be controlled from a surface vessel through an umbilical cord. Recent test data obtained from the HUC system operated in a controlled underwater environment will be presented along with measured performance characteristics.