基于辐射传输数值模型PCOART的大气漫射透过率精确计算

EXACT CALCULATION OF ATMOSPHERIC DIFFUSE TRAN-SMITTANCE BASED ON RADIATIVE TRANSFER NUMERICAL MODEL PCOART

分析了中国第一颗海洋水色卫星(HY-1A)大气漫射透过率模型的计算精度,结果表明,当气溶胶光学厚度或天顶角较大时,该模型计算相对误差可>5%,最大可达50%以上,不适用于高纬度海区(纬度>60°).在此基础上,利用海洋-大气耦合矢量辐射传输数值计算模型PCOART,进行了大气漫射透过率的精确计算.通过与SeaWiFS精确大气漫射透过率查找表计算结果的比较,表明利用PCOART计算大气漫射透过率的相对误差<1.5%,且当观测天顶角<60°时,相对误差<0.5%,可以用来生成我国海洋水色卫星遥感器的精确大气漫射透过率查找表.

The accuracy of the atmospheric diffuse transmittance model for Chinese first ocean color satellite HY-1A was analyzed. Our results show that the relative error of this model exceeds 5% with the maximum more than 50% when the aerosol optical thickness or viewing zenith angle is large, which means that this model can＇t be used in high latitude sea. Then, by using the coupled ocean-atmosphere vector radiative transfer numerical model （PCOAT）, the atmospheric diffuse transmittance is exactly calculated. By comparing with SeaWiFS exact atmospheric diffuse transmittance look-up table, the results show that the relative error of this model is all less than 1.5%. And when the viewing zenith angle is less than 60°, the relative error is less than 0.5%, which proves that this model can be used to generate the exact atmospheric diffuse transmittance look-up table for Chinese ocean color remote sensor.