Wa-LiD: A New LiDAR Simulator for Waters

A simulator (Wa-LiD) was developed to simulate the reflection of LiDAR waveforms from water across visible wavelengths. The specific features of the simulator include 1) a geometrical representation of the water surface properties; 2) the use of laws of radiative transfer in water adjusted for wavelength and the water's physical properties; and 3) modeling of detection noise and signal level due to solar radiation. A set of simulated waveforms was compared with observed LiDAR waveforms acquired by the HawkEye airborne and Geoscience Laser Altimeter System (GLAS) satellite systems in the near infrared or green wavelengths and across inland or coastal waters. Signal-to-noise ratio (SNR) distributions for the water surface and bottom waveform peaks are compared with simulated and observed waveforms. For both systems (GLAS and HawkEye), Wa-LiD simulated SNR conform to the observed SNR distributions. Moreover, Wa-LiD showed a good ability to reproduce observed waveforms according to some realistic water parameters fitting.