Ocean water clarity measurement using shipboard LIDAR systems

Experiments with two laser radar systems were conducted off the coast of Key West Florida in May of 2001. The purpose of the test was to observe the effect of the water optical properties on the Lidar return signal decay rate and compare the performance of the two systems. The first Lidar system, the Shipboard K-meter Survey System (KSS), was configured to transmit linearly polarized light and to receive backscattered light in both channels. The second system, the Airborne KSS, is designed to conduct global surveys from patrolling P3-C aircraft. For this test the Airborne KSS was specially configured to operate from the deck of a ship and both systems were operated in conjunction with each other. The Shipboard KSS was configured with a remotely controlled mechanical iris in both receiver channels to allow the use of different fields of view in each channel Several oceanographic in-situ instruments were used to measure such water properties as optical transmission and absorption, backscatter coefficient, diffuse attenuation, temperature, and salinity as functions of depth. This in-situ data was then compared with the Lidar measurements.