基于显著光谱差异人工靶标的遥感器在轨光谱辐射定标方法研究

Quantitative remote sensing plays an crucial role in the research of global climate change and the evolution of the biosphere. Radiometric calibration is a prerequisite for quantitative remote sensing. Sensor’s spectral response and radiometric calibration are closely related. For the general radiometric calibration methods having not considered the spectral degradation，a new calibration method based on spectral different artificial tarps is established in this paper. Firstly, a spectral degradation descriptive model is established, then multiple spectral different tarps are used as calibration reference, by statistically analyzing the calibration coefficient sequence calculated，combined with the specific solving algorithm and the spectral response measured before launch, a new radiometric calibration coefficient which contains spectral degradation can be obtained at last. The method of selecting specific spectral tarps is also established in this paper, with which the "individual calibration" thinking can be achieved. The new calibration method proposed here can further improve the radiometric calibration level of our country, and can also give technology support for the high precision remote sensing of global atmosphere.

定量遥感在全球气候变迁、生物圈演化研究中扮演了关键性的角色。而辐射定标是定量化遥感的前提，载荷光谱响应函数与辐射定标过程密切相关，针对现有辐射定标方法没有考虑遥感器光谱响应函数退化的问题，本课题提出了基于显著性光谱差异人工靶标的在轨定标方法。本文首先建立合适的退化描述模型，以多个具有显著性光谱差异的人工靶标作为检测参照，通过对得到的定标系数序列进行统计，结合相应的模型求解算法和发射前光谱响应函数的测量结果，得到包含退化效应评估的辐射定标系数。本课题还针对遥感器的辐射和光谱特性建立了光谱靶标选择方法，实现了“个体化检校”的思想。利用本课题的定标方法可进一步提高我国辐射定标水平，为保障全球大气环境高精度定量遥感监测提供了技术支持。

遥感器在轨运行期间，其光谱响应特性会产生变化导致辐射定标精度下降，本项目提出了基于人工光谱靶标的在轨光谱辐射定标方法，利用光谱靶标的非线性特性来实现遥感器的在轨检测，通过建立校正模型以及在轨实验验证，取得了初步的成果，该方法可有效实现对多光谱遥感器光谱响应特性的在轨校正，反演反射率精度得到了较大程度的提高，该方法可应用于星上定标以及基于时间序列的在轨替代定标过程中.