Modeling of als intensity behavior as a function of incidence angle for coastal zone surface study

Backscatter intensity of the LiDAR, recorded simultaneously with the discrete topography measurements, was recently investigated, providing complementary information to study coastal environments. The aim of this study was (i) to analyze the intensity-incidence angle behavior for coastal environments (sea and moist sand surfaces) and other surfaces (fields and urban area) with different reflectance models and (ii) to choose the best modeling for all these surfaces. We compared three reflection models. Firstly, diffuse reflection is introduced by Lambert´s cosine law. The illuminated surfaces are composed of numerous small mirror-like facets inducing a dominant specular diffusion. This scattering of micro-facets is defined by the Beckmann distribution. The last model is a combination of diffuse and specular reflection. In this paper, we found that Beckmann distribution well simulates the intensity-incidence behavior for specular and diffuse mechanisms with the advantage to have only one parameter to characterize the studied surfaces.