风云静止气象卫星的图像导航和大气运动矢量(特邀)  

Image Navigation and Atmospheric Motion Vectors for FY Geosynchronous Meteorological Satellites(Invited)

作　　者：许健民[1] 陆风[1] 杨磊[1] 张晓虎[1] 曹赟 张其松[1] 商建[1] Xu Jianmin;Lu Feng;Yang lei;Zhang Xiaohu;Cao Yun;Zhang Qisong;Shang Jian(National Satellite Meteorological Center,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]中国气象局国家卫星气象中心,北京100081

出　　处：《光学学报》2024年第18期1-15,共15页Acta Optica Sinica

基　　金：国家自然科学基金(40275007,40275036);国家重点研发计划资助(2021YFB3900400,2021YFB3900402)。

摘　　要：本文介绍了风云静止气象卫星图像配准定位和大气运动矢量的算法。图像配准和定位统称图像导航,是图像观测的重要步骤。图像导航的数学模型须要在每一个观测瞬间,获得卫星的位置以及从卫星指向观测目标物的矢量。风云二号是自旋稳定卫星,它用图像上地球影像中心位置的时间序列求解卫星的姿态,并对图像进行定位。风云四号是三轴稳定卫星,存在影响卫星对地观测光路指向的因素。所以风云四号卫星的观测和图像定位,通过更加密切的星地协同操作实现。在连续的图像上追踪云的运动,获得大气运动矢量。大气运动矢量所在的高度,是用物理方法确定的。从密实云上行的辐射,主要来自云。把云的温度与数值预报模式中各个高度层面上的温度相匹配,得到云的高度。从半透明的薄云上行的辐射,一部分来自云体,其余部分来自云下的背景。云的半透明程度主要和云的密实程度有关,所以在窗区和半透明通道的卫星测值之间,存在线性相关关系。据此可以更加准确地计算出云的半透明程度,以及在云的高度上大气的温度。半透明云高度计算方法的改善,提高了大气运动矢量的精度。Significance Geosynchronous meteorological satellites,operating at an altitude of 35800 km above the equator,frequently capture images of the Earth disk.The successive image derives atmospheric motion vectors.They have been monitoring various weather systems continuously and are indispensable tools for precise weather forecasting.Our study shows image navigation and atmospheric motion vector algorithms for FY geosynchronous meteorological satellites.Progress The geosynchronous satellite takes Earth observation pixel by pixel.The observation pixels are assembled to form images.The image assembling contains two major components:image registration and image navigation.Image registration refers to the process of ensuring that each pixel within an image is correctly aligned with its nominal Earth location within a specified accuracy,which measures pointing stability.Image navigation involves determining the location of each pixel within an image in terms of Earth latitude and longitude,which measures absolute pointing accuracy.Both image registration and navigation are critical steps in image assembling,impacting all subsequent data processing procedures and product quality.Due to the satellite’s considerable distance from Earth,the accuracy of attitude determination significantly affects image navigation quality.Precise image navigation requires accurate measurement of the position and the attitude of the satellite at any observation time.The FY-2 satellite has a spin-stabilized attitude.The Earth position within the image is used to determine the attitude of the satellite.The time series of the satellite orientation relative to the centerline of the Earth disk provides information on the attitude parameter in the north-south direction.The angle between the sun and the Earth serves as a reference for aligning the Earth observation pixels position in the scan line together with the attitude parameter in the east-west direction.The solution to the image navigation model requires the parameters to be well-defined,meas

关 键 词：静止气象卫星 图像配准 图像定位 大气运动矢量 

分 类 号：P414.4[天文地球—大气科学及气象学]