INDEPENDENT ON-ORBIT GEOMETRIC CALIBRATION OF OPTICAL SATELLITE BASED ON WEIGHTED VIRTUAL OBSERVATION

Abstract

On-orbit geometric calibration is an essential technology to improve the initial geometric accuracy of the optical satellite images. The presented methods usually take the absolute constraint from calibration site data into the imaging model to deduce exact systematic error parameters. However, the characteristic of strong dependence on the high-accuracy calibration site data leads to limitations such as high cost and poor efficiency of these conventional methods. In order to make better use of the mutual constraints among the images, and to get rid of the dependence of calibration site, we conduct an investigation on the on-orbit geometric calibration using the mutual constraints of overlapped images instead of absolute constraint from calibration site for optical satellite. To ensure the stable solution of calibration equation, a weighted virtual observation is introduced into calibration model to improve its condition. The method is verified with a pair of simulated images, and the satisfactory results indicate that the method is effective and reasonable.