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。     

Radiometric calibration of hyper-spectral imaging spectrometer based on optimizing multi-spectral band selection

Hyper-spectral imaging spectrometer has high spatial and spectral resolution. Its radiometric calibration needs the knowledge of the sources used with high spectral resolution. In order to satisfy the requirement of source, an on-orbit radiometric calibration method is designed in this paper. This chain is based on the spectral inversion accuracy of the calibration light source. We compile the genetic algorithm progress which is used to optimize the channel design of the transfer radiometer and consider the degradation of the halogen lamp, thus realizing the high accuracy inversion of spectral curve in the whole working time. The experimental results show the average root mean squared error is 0.396%, the maximum root mean squared error is 0.448%, and the relative errors at all wavelengths are within 1% in the spectral range from 500 nm to 900 nm during 100 h operating time. The design lays a foundation for the high accuracy calibration of imaging spectrometer.