The Nonlinear Effective Attenuation Coefficient of Spaceborne Oceanic Lidar Signal

摘要

Multiple scattering is an inevitable effect in spaceborne oceanic lidar because of the large footprint size and the high optical density of seawater. The effective attenuation coefficient k_(lidar) in oceanic lidar equation, which indicates the influence of the multiple scattering effect on the formation of lidar returns, is an important parameter in the retrieval of inherent optical properties (IOPs) of seawater. In this paper, the nonlinearity of k_(lidar) and the relationships between k_(lidar) and the IOPs of seawater are investigated by solving the radiative transfer equation with an improved semianalytic Monte Carlo model. k_(lidar) is found to decrease exponentially with the increase of depth in homogeneous waters. k_(lidar) is given as an exponential function of depth and IOPs of seawater. The results in this paper can help to have a better understanding of the multiple scattering effect of spaceborne lidar and improve the retrieval accuracy of the IOPs of seawater using spaceborne lidar.