Imaging Navigation and Registration for Geostationary Imager

The Fengyun-4 satellite (FY-4) is a part of the new generation of the Chinese geostationary meteorological satellites program. The key indicators of the satellite include image navigation and registration (INR), which represent the absolute and relative spatial correspondence between the remote sensing image and the ground target. The most complicated factor affecting INR accuracy involves instrument deformation caused by changes in thermal and mechanical environments in orbit. In the letter, the distorted optical path of the 2-D scanning mechanism of instrument is modeled, and the compensation algorithm represented by two angles and seven equivalent parameters is discussed. In the modeling, more detail deformation is considered, the redundancy is reduced, and the stability of parameter identification is improved compared with another method typically used in American and European satellites. Furthermore, the study presents the processing of the equivalent parameter identification by sensing the image of crossing stars.