风云卫星载荷反射波段在轨精细化定标模型研究

项目名称： 风云卫星载荷反射波段在轨精细化定标模型研究

项目编号： No.41471303

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： 孙凌

作者单位： 国家卫星气象中心

项目金额： 86万元

中文摘要： 面向制约遥感应用的辐射精度和稳定度问题，针对风云三号卫星中分辨率光谱成像仪反射波段在轨定标分析数据所体现的周期性震荡现象，在发射前和星上定标测量不足的情况下，以高精度大气顶辐射传输模拟为基准，进行精细化定标关键环节（温度、角度和偏振敏感、时间衰变等）的分解，研究遥感器在轨的温度、角度和偏振的敏感特性，发现反射波段在轨辐射定标的深层次影响机制；建立包括时间趋势校正、温度校正，以及角度和偏振校正等在内的遥感器反射波段在轨精细化定标模型，基于大数据量辐射数据最优化求解，完成精细化定标模型参数的协同调整；并基于地球系统的稳定性，以辐射敏感的海洋反演产品时空特征为参考，完成遥感器长时间序列数据的辐射质量诊断和评估。本研究将建立基于地球目标观测的反射波段精细化辐射定标参数在轨反演方法，深化对遥感器在轨辐射特性的刻画和变化机制的认识，提高遥感器辐射观测数据质量，并为遥感器研制和运行提供科学依据。

中文关键词： 辐射定标；可见光-近红外遥感；星上定标；交叉定标；偏振定标

英文摘要： The radiometric accuracy and stability are the bottleneck problem that restricts the effective application of satellite remote sensed data. In the post-launch calibration analysis of MEdium Resolution Spectral Imager (MERSI) onboard FY-3, periodic oscillations are found. Under the circumstances that the prelaunch and onboard radiometric calibration measurements are insufficient, the high-quality top-of-the-atmosphere radiances simulated by radiometric transfer models are taken as the on-orbit radiometric reference. Various key factors in the process of elaborated radiometric calibration such as temperature, incident angle and polarazation sensitivities, as well as temporal degradation, are separated and studied in order to find their impact mechanism of on-orbit radiometric calibration. The elaborated on-orbit calibration model are constructed including corrections for temporal variation, temperature, incident angle and polarization sensitivities. The parameters of the elaborated model are adjusted synergistically based on the large amount matched radiometric dataset using the optimization method. Based on the fact that the earth system is relatively stable, the long-term radiometric quality of satellite data is diagnosed and evaluated using the spatial-temporal characteristics of ocean color products which are sensitive to radiometric bias. In this project, the on-orbit retrieval method for the elaborated radiometric calibration model will be presented using earth view observations. With the further knowledge about the radiometric characteristics and variation mechanism of the filtered scanning radiometer, the quality of the satellite radiometric observations will be improved, and scientific evidences will be provided to promote the satellite sensor manufacturing and operating.

英文关键词： radiometric calibration;visible and near-infrared remote sensing;on orbit calibration;cross calibration;polarimetric calibration