Monte Carlo approach for solving the radiative transfer equation over mountainous and heterogeneous areas

An algorithm based on the Monte Carlo method is developed to solve the radi ative transfer equation in the reflective domain (0.4-4 mu m) of the solar spectrum over rugged terrain. This algorithm takes into account relief, spa tial heterogeneity, and ground bidirectional reflectance. The method permit s the computation of irradiance components at ground level and radiance ter ms reaching an airborne or satelliteborne sensor. The Monte Carlo method co nsists of statistically simulating the paths of photons inside the Earth-at mosphere system to reproduce physical phenomena while introducing neither a nalytical modeling nor assumption. The potentialities of the code are then depicted over different types of landscape, including a seashore, a desert region, and a steep mountainous valley. (C) 1999 Optical Society of America OCIS codes: 010.1300, 280.0280, 000.5490.