近地面水平方向大气偏振辐射传输仿真与验证

Simulation and validation of atmospheric polarized radiative transfer in horizon orientation near ground

近地面水平方向偏振成像是地基目标观测的有效手段之一。目标偏振信息在大气传输中受到大气气溶胶及分子等散射和吸收作用的影响,叠加了非目标偏振信息,干扰了目标本身偏振特性参数的提取。因此,对大气的偏振影响研究具有重要意义。针对近地面水平方向偏振观测,基于单次散射假设,仿真计算了不同气溶胶光学厚度条件下的大气偏振辐射传输特性,并开展了外场偏振特性传输实验验证。仿真结果表明,地表贡献可以忽略;随着气溶胶光学厚度的增大,大气对总偏振反射的贡献越大;针对外场实验,仿真计算了不同时序同等观测条件下的线偏振度值,与实测结果相对误差在±0.1范围内,一致性很好。研究结果为近地面偏振特性传输研究提供了理论支持,并为近地面偏振观测中的大气校正奠定了基础。

Polarized imaging in horizontal direction is an effective method to observe targets at ground.Due to the scattering and absorbing effects of aerosol and molecule in the atmospheric transfer path,the target polarized information composies other polarized information,which would limit the characteristics extraction of targets.It is very important to study the effects of atmospheric polarization.For the problem of polarized observation in horizontal near ground,the atmospheric transfer properties under different aerosol optical depth were simulated based on the single scattering hypothesis.And the experiment on atmospheric polarized properties transfer was performed outdoor.The result of simulation indicates that the contribution of surfaces could be ignored;the contribution of atmosphere to total polarized reflectance increases with the increase of the aerosol optical depth.The value of degree of line polarization which was simulated under the same observing conditions with the experiment outdoor at different time,was consistent with the experiment,and the relative error was in the range±0.1.The basic theory of investigation on both polarized radiative transfer and atmospheric correction near ground was proposed.