Instrument: Light Detection and Ranging System

The Light Detection and Ranging (LIDAR) system is an active remote sensing system that can be operated in either a profiling or scanning mode using pulses of light to illuminate the terrain. LIDAR data collection involves mounting an airborne laser scanning system onboard an aircraft along with a kinematic Global Positioning System (GPS) receiver to locate an x, y, z position and an inertial navigation system to monitor the pitch, roll, and heading of the aircraft. By accurately measuring the round trip travel time of the laser pulse from the aircraft to the ground, a highly accurate spot elevation can be calculated. Depending upon the altitude and speed of the aircraft along with the laser repetition rate it is possible to obtain point densities that would likely take months to collect using traditional ground survey methods (June 2010 definition from: http://www.ngs.noaa.gov/RESEARCH/RSD/main/lidar/lidar.shtml).The LIDAR transmitter uses a Galium-Aluminum-Arsenic laser which emits energy in pulses at a constant rate and wavelength. The LIDAR has two sounding modes: active and acoustic. Note: A LIDAR system was used during US JGOFS Arabian Sea cruises to acquire SST, DOM and fluorometric pigment data, but there are also bathymetric LIDAR systems.