地表物体具有较强的偏振特性, 因此可以作为偏振遥感的信息源。但是, 大气的偏振效应强于地表的偏振效应, 导致星载遥感器无法有效接收地表目标的偏振信息, 大气的起振与退偏效应成为偏振遥感对地表目标进行观测和应用的一个瓶颈问题。本文提出一种利用大气中性点对偏振遥感中地表偏振效应与大气偏振效应进行分离的方法, 通过天空中大气线偏振度为零的中性点区域进行对地观测, 目的是去除大气偏振作用, 进而最大限度地获取地表目标偏振信息。地面实验的结果验证了利用大气中性点进行大气纠正具有理论上的可行性。

Polarized reflectance of land surface is essential to remote sensing, despite the fact that the reflectance information received by polarimeter is always overwhelmed by atmospheric polarization effect, which is stronger than that of the land objects. Subtracting the atmospheric effect, therefore, is a bottleneck problem in the polarization remote sensing over land surface. Atmospheric neutral point, which refers to a position where the skylight is unpolarized, is introduced in this paper as a tool for separating the polarization effect between objects and atmosphere. The ground experimental results show that when observing the land surface from neutral point, the polarization effect of the atmosphere is reduced to zero and the polarization information of land surface is maximized. The results indicated the feasibility of using atmosphere neutral points for atmospheric correction over land surface.