全极化微波辐射计姿态对观测亮温的影响及消除

Eliminating the influence of attitude on brightness temperatures measurement for polarimetric microwave radiometer

针对仝极化微波辐射计精确探测的需求,研究了辐射计姿态对于观测亮温的影响以及亮温误差校正.建立了姿态偏移与观测入射角以及极化旋转角的关系,模拟了观测亮温随观测入射角以及极化旋转角波动的变化;仿真了姿态偏移情况下的辐射计原始观测亮温;运用一种基于辐射传输模型的姿态补偿方法,以垂直极化亮温和第三Stokes参数亮温为例,对原始观测亮温展开误差校正.研究显示,该方法能够有效去除辐射计姿态偏移对观测亮温造成的影响,校正结果满足辐射计数据预处理的误差精度要求.

In order to meet the requirement of accurate detection for polarimetric microwave radiometer,in this paper,we study on the influence of attitude on brightness temperatures received by the radiometer.Correction for brightness temperatures errors is also analyzed.The relationship between the misspecification of the attitude and the incidence angle together with polarization rotation angle is established.The variation of brightness temperatures with the change of incidence angle and polarization rotation angle is simulated. We simulate the original observational brightness temperatures of the radiometer.A method based on the radiative transfer model for compensating attitude offset to correct brightness temperatures errors is presented.Taking vertical brightness temperature and the third Stokes parameter brightness temperature for example,our method can eliminate the influence of attitude offset on the observation of brightness temperatures effectively,the result can satisfy the accuracy requirement of data preprocessing for polarimetric microwave radiometer.