机载大气红外高分辨率光谱的信息量分析

Information analysis of airborne atmosphere infrared high resolution spectral

机载红外高分辨率干涉光谱仪(HIS)是遥感大气信息的大气红外背景辐射测量装置。基于HIS红外高光谱大气数据,对大气温度和主要大气吸收气体进行了敏感性分析;并通过引入信息容量的概念,利用一维变分方法,对HIS测量装置遥感探测大气参数的能力进行评估,定量描述了HIS测量的红外光谱反演大气温度和水汽的信息容量、自由度和垂直分辨率等信息,其中温度、水汽的信息容量分别为49.5、25.2;自由度分别为10.5、5.6,温度的平均垂直分辨率为2.2 km,水汽的垂直分辨率为2 km;讨论了HIS的反演精度与仪器测量误差之间的关系,获取了大气温湿廓线的最小可探测精度。

Airborne High-spectral Interferometer Sounder(HIS)is a detector designed to measure the infrared atmospheric background radiation in nadir viewing mode.Based on HIS infrared high-resolution spectral data,sensitivity analysis of atmospheric temperature and major atmospheric absorbers were carried out.By introducing the concept of information content and using the 1D-VAR method,the ability of detecting atmospheric parameters was analyzed with HIS measurment.The information content,degree of freedom and vertical resolution of temperature and water vapor have been used to characterize the observation system.The information content of temperature and water vapor was 49.5 and 25.2 respectively,the degree of freedom was 10.5 and 5.6 respectively,the average vertical resolution of temperature was 2.2 km,and the average vertical resolution of water vapor was 2 km.The relationship between the inversion accuracy and the instrument noise was discussed.It shows the minimum measurable accuracy of retrieved temperature and humidity profile.