Developing Testing a Pushbroom Camera Motion Control System: Using a LIDAR Based Streak Tube Camera For Studying The Influence of Water Waves On Underwater Light Structure Detection

摘要

A pushbroom sensor motion control system was developed for use in conjunction with a pulsed laser fan beam, streak tube camera, and a high speed low light level camera. The LIDAR and camera control system was tested to study the influence of water waves upon active-passive remote sensing systems and associated models that require pushbroom sensor motion. A pulsed laser fan beam signal at 532 nm was recorded using a streak tube camera and a (high speed, low light level, high quantum efficiency) digital CCD camera. Tests were conducted in 3 different water tanks, including 2 tanks with water waves (the longest wave tank or channel is 60 m long). Capillary waves, "1 cm wavelength) were generated using an acoustic wave source generator. Streak tube camera and CCD images were collected in conjunction with a 532 nm pico-second short pulse laser. Images collected demonstrate the pulse stretching around submerged water targets as well as the ability to discriminate water depth of submerged targets in shallow water types. In turbid water, the pulsed layer backscatter structure showed a nearly random return as a function of depth if the signal was attenuated before reaching the bottom of the water column. The data collected indicated the motion control tes ting system can accommodate a variety of cameras and instruments in the lab and in the outdoor water wave channel. Data from these camera systems are being used to help validate analytical and Monte Carlo models of the water surface structure, and the underwater light field structure (pulse stretching) as well as to validate other LIDAR applications used in bathymetric and hydrographic surveys of coastal waters and marine inlets for physical and biological (submerged vegetation) surveys.