七通道微波辐射计遥感大气温度廓线的性能分析

文中首先分析了大气参数分布的垂直分辨率对模拟七通道微波温度探测器各通道亮温的影响，通过对比计算表明，大气参数的垂直分辨率对微波测温通道亮温计算的影响为0．2K～0．7K；随后分析了各通道亮温测量误差对温度廓线反演性能的影响，当测量误差在0．2K～2．0K范围内变化时，反演结果的总体均方根误差为2．1K～3．1K；同时还分析了单通道缺损、单通道发生漂移及所有通道发生漂移等情况对温度廓线反演性能的影响。当仪器缺损一个通道时，对所缺通道权重函数峰值附近高度上的大气温度反演有不同程度的影响，对其他高度上的大气温度反演的影响可忽略；单通道漂移0．5K时，对反演结果的影响较小；各通道整体漂移达到1．0K时，对温度廓线反演有明显影响；最后，考虑了云雾对微波测温通道亮温的影响，数值计算表明，雾层、浓霾和卷云对各通道亮温几乎没有影响，层云和积云对50．50GHz通道亮温有明显的影响。

ANALYSIS OF THE REMOTE SENSING OF ATMOSPHERIC TEMPERATURE PROFILES USING THE SEVEN CHANNEL MICROWAVE RADIOMETER

The effect of the vertical resolution of the atmospheric parameter profiles on the simulation of the microwave brightness temperatures is analyzed firstly. The calculation shows that the root mean square differences of the simulated brightness temperatures due to the vertical resolution of the profiles are 0.2~0.7 K. With the numerical experiment used to analyze the effects of the measurement errors of the brightness temperatures of each channel on the retrieval of the atmospheric temperatures, it is shown that the total root mean square retrieval errors are 2.1~3.1 K while the measurement errors of brightness temperatures are 0.2~2.0 K. Furthermore, the effects of the single-channel loss, the single-channel offset and the all-channel offset on retrieving temperature profiles are analyzed. While one channel is lost, there are different effects on the retrieval of the atmospheric temperatures at the levels in the vicinity of the peaks of the weighting functions, and the effects at the other levels can be ignored. While the brightness temperature of any one channel is offset 0.5 K, the effect on the retrieval is slight. While all channels are simultaneously offset up to 1.0 K, the effect is remarkable. Lastly, the results of the numerical calculation indicate that the fog, haze and cirrus cloud have few effects on the brightness temperatures of the microwave channels, while the stratus and cumulus clouds have remarkable effects on the brightness temperatures at 50.50 GHz .