传递辐射计光谱通道的优化设计

鉴于传递辐射计对成像光谱仪定标时其通道选择对成像光谱仪的定标精度具有重要影响,本文使用MATLAB语言编写评价函数,作为对3 000K黑体光谱曲线进行多光谱反演精度的评价标准,最后利用MATLAB遗传算法和模式搜索算法工具箱对评价函数寻找最小值解,即传递辐射计的最优通道选择,并根据评价函数对光谱通道数、中心波长偏移、带宽展宽和测量系统误差对光谱反演精度的影响进行分析。结果表明,为实现0.12%的光谱反演精度,要求传递辐射计中心波长的偏移量不超过0.2nm、带宽展宽不大于0.02nm,测量系统误差小于0.1%。本研究可以指导传递辐射计的设计,对提高地球成像光谱仪的定标精度具有重要意义。

Optimization of spectral channel of transfer radiometer

As channel selection acts an important influence on calibration accuracies in the calibration of imaging spectrometers by transfer radiometer ,herein MATLAB language was adopted to compile a merit function ,which was used as the evaluation standard of inversion accuracy of the spectral curve of a blackbody at a temperature of 3000k .The MATLAB genetic algorithm and the pattern search algorithm toolbox were employed to solute the minimal value of function that was the optimal spectral channel distribution of the transfer radiometer .Finally ,influence factors of the number of spectral channels ,including the shifting of center wavelength ,the broadening of bandwidth and measurement system error ,were analyzed .The results show that the spectral inversion accuracy of is 0 .12% ,when the shifting of center wavelength does not exceed 0 .2 nm ,the broadening of bandwidth is not more than 0 .02 nm ,and the system error is less than 0 .1% .This study can guide the design of transfer radiometers and has a great significance to improve the calibration accuracy of earth imaging spectrometers .