Simulation of Glint Reflectance and Determination of Water Surface Roughness over Turbid Coastal and Inland Aquatic Systems

Zhenyi Lin1, Knut H Stamnes2, Wei Li2, Charles K Gatebe3 and Rajesh Poudyal4, (1)Stevens Institute of Technology, Union City, NJ, United States, (2)Stevens Institute of Technology, Hoboken, NJ, United States, (3)Universities Space Research Association Greenbelt, Greenbelt, MD, United States, (4)SSAI, NASA GSFC, Greenbelt, MD, United States
Satellite remote sensing under glint conditions remains a challenging problem. Current glint correction algorithms rely on a crude estimation of the glint radiance. Measurements of complete sets of the bidirectional reflectance distribution function (BRDF) were obtained from the NASA Cloud Absorption Radiometer (CAR) deployed on an aircraft. We use an optimized version of the Discrete-Ordinate (DISORT3) Radiative Transfer Model (RTM) with a pseudo two-dimensional BRDF to simulate ocean glint reflectances measured at a near IR wavelength. The RTM was used for the first time to successfully reproduce the measurements by matching model outputs with observations. In addition, the RTM simulations were used to retrieve sea surface roughness and other parameters through a nonlinear Levenberg-Marquardt regression method.