几种海水微波复介电常数模型的比较和分析

Comparison and Analysis of Several models for Microwave Complex Dielectric Constant of Sea Water

海水的复介电常数是计算海面发射率的重要输入参数之一。迄今为止,已经发布了许多经典的海水复介电常数计算模型,并被广泛应用在星载微波海洋遥感领域。首先回顾了经典的海水微波复介电常数模型,指出了它们的主要性能特点和彼此之间的差异;接着,使用卫星观测数据以及相匹配的大气海洋环境产品,通过比对模型计算亮温和卫星实测亮温,分析了当前5个海水微波复介电常数模型的计算准确度。结果表明:Fastem5中的海水微波复介电常数模型计算准确度相对较高,运行速度较快。

For a flat ocean surface,the emissivity can be accurately calculated from the Fresnel formula for a given seawater complex dielectric constant and a local incident angle.Consequently,the microwave complex dielectric constant of sea water is an important input parameter for sea surface emissivity.As far,many classic seawater complex dielectric constant models have been released,which are widely applied in spaceborne microwave ocean remote sensing field.Firstly,some classic models and their main characteristics and differences were reviewed.Secondly,using the satellite data and collocated atmospheric and oceanic products,the simulation accuracy of the five classic models was analyzed by comparing calculation and measurement of WindSat brightness temperatures.The results show that the microwave seawater complex dielectric constant model in Fast Emissivity Model-5has relatively higher calculation accuracy and more faster running speed.