环境参数对L波段盐度计观测亮温的影响研究

Effects of Environmental Parameters on Observation Brightness Temperature of Space-borne Ocean Salinity Meter at L-Band

星载海洋盐度计依据海表面盐度在微波波段的辐射特性,通过构建海面微波辐射探测器,利用海面辐射亮温、海表面粗糙度以及海面温度等信息反演得到海表面盐度,是实现全球海洋盐度观测的有效手段。构建合理的星载L波段盐度计辐射传输正演模型是准确定量反演海表盐度的基础,卫星盐度计观测亮温不仅与卫星固有参数有关,还与海洋、大气及空间因素密切相关。为了研究外界环境因素(海表盐度、温度、海面风场、海面气压、海表气温、大气水汽含量、降雨以及法拉第旋转角等)对盐度计观测亮温的影响,文中基于L波段盐度计辐射传输正演模型以及MPM93大气毫米波传播模型,通过敏感性分析,研究星载盐度计在不同环境条件下的参数敏感性,为减小外界因素对海表盐度反演精度的不利影响提供理论依据。

The space-borne ocean salinity meter based on the radiation characteristics of sea surface salinity in the microwave band, through the construction of sea surface microwave radiation detector, uses sea surface brightness temperature, sea surface roughness and surface temperature information to retrieve sea surface salinity,which is an effective way to realize the global ocean salinity observation. Construction of the reasonable L-band forward model of brightness temperature is the foundation of accurate and quantitative inversion of sea surface salinity. The observation brightness temperature of space-borne salinity meter is not only related to the satellite intrinsic parameters, but also closely related to the ocean, atmosphere and space factors. In order to study the influence of environmental factors（sea surface salinity, sea surface temperature, sea surface wind, sea level pressure, sea level temperature, total precipitable water vapor content, rainfall and Faraday rotation angle） on the observation brightness temperature of space-borne salinity meter, the parameter sensitivity in different environmental conditions is researched through sensitivity analysis, which is based on L-band radiative transfer model and MPM93 atmospheric millimeter wave propagation model. The results provide a theoretical basis for reducing the adverse effects on sea surface salinity retrieval from external environmental factors.