基于变分原理的星载遥感器红外通道在轨光谱定标方法研究

项目名称： 基于变分原理的星载遥感器红外通道在轨光谱定标方法研究

项目编号： No.41471304

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 徐娜

作者单位： 国家卫星气象中心

项目金额： 87万元

中文摘要： 光谱响应特性是卫星资料应用中一个非常重要的参数，决定了遥感器能够探测到的特征辐射。研究表明，卫星发射后遥感器光谱响应可能发生显著变化，造成观测偏差可达2-3K,而定量应用误差可达30%,严重影响卫星数据质量及其定量应用效果。由于缺乏星上光谱测量装置，红外通道光谱响应无法实现在轨测量。项目从定量遥感的需求出发，基于一维变分原理，针对通道式遥感器研究其红外通道在轨光谱定标方法，发展基于高光谱同步观测资料的光谱响应函数的数值求解算法，实现对光谱漂移和形变误差的同时订正，并以风云卫星载荷为例实现算法应用和验证。通过对样本获取、模拟计算、解算模型构建与方程求解以及误差控制等几个方面的深入研究，确保数值求解算法的可行性以及解算结果的可靠性。本项目的实施可解决通道式遥感器无法实现在轨光谱定标的难题，有助于提高卫星数据质量以及定量产品精度，不仅具有较高科学研究意义，更具广泛业务推广价值。

中文关键词： 热红外遥感；光谱定标；高光谱互定标；一维变分；星上定标

英文摘要： The sensor spectral performance determines the outputs from scenes, as well as the calibration targets that are used to calculate the calibration coefficients in the radiometric calibration. It is significant for radiometric calibration, and high quality radiometric radiance requires accurate spectral and radiometric calibrations. However, the spectral response function (SRF) used in the radiometric calibration may not always accurately characterize the actual in-orbit instrument spectral performance, due to the possible inaccurate spectral calibration before satellite launch, and/or possible SRF change caused by the harsh space environment. Recent researches indicate that the real SRF may present a large shift of 10cm-1 from the laboratory measurement, thus lead to an approximate 2-3K bias in the calibrated radiance, and about 30% relative errors in the quantitative applications. As there's no spectral measurement assembly onboard for thermal infrared channels, on-orbit spectral response monitoring and correcting are diffcult. On requirements of quantitative remote sensing, an on-orbit spectral calibration method is brought out for thermal infrared channels. And it is developed to retrieve on-orbit spectral response functions using co-located high spectral resolution observation data based on one dimensional variational theory (1DVR), which can help to correction the spectral errors both in spectral drift and deformation. To make sure the feasibility of the numerical model and the reliability of the retrieval results, more details are carefully considered in this project, i.e., observation samples acquiring and radiance simulation, 1DVR numerical model construction and its solving method, as well as error control and so on. The implementation of this project can solve the in-orbit thermal infrared spectral calibration problem of broadband sensor, and help to improve the quality of satellite data and promote its quantitative application ability. It not only has high scientific research significance, and more practical value.

英文关键词： Thermal Infrared Remote Sensing;Spectral Calibration;Hyperspectral Inter-calibration;One Dimensional Variation(1DVAR);On-orbit Calibration