在分析光学遥感仪器探测信息中主要噪音源的基础上,提出了一种改进空间结构函数分析的仪器探测灵敏度在轨评价方法,包括:基于多项式递推分解的整体噪音估计模型,以及减小系统误差及修正模数转换噪音影响等基本技术途径.仿真结果证实,该改进算法的噪音估计准确度优于传统的高斯估计和基于外推的结构函数分析方法.针对实际观测数据,在去除模数转换噪音影响后,仪器噪音等效温度差指标的在轨评价准确度可达±0.05K.该评价方法已在FY-2D静止气象卫星在轨测试中得到成功应用.
Based on the analysis of noise sources for optical remotely-sensed instrument, an improved spatialstructure function (ISSF) approach for detection sensitivity evaluation of on-orbit instrument is proposed, which includes the model of noise estimation with polynomial iterative decomposition and the decrease and modification way for both systematic error and analog-to-digital conversion (ADC) noise. It is shown from simulation results that the accuracy of noise estimation is better than that of both Gauss statistics and spatial-structure based on extrapolation. Further, by analyzing some real observed data with the effects of ADC noise removed,the accuracy of the evaluated noise equivalent different temperature (NEAT) is about ± 0. 05K. This approach has been applied in the on-orbit ground testing of FY-2D geostationary meteorological satellite successfully.