Exterior orientation elements´ Bayesian estimation model under insufficient ground control points

It is crucial to estimate the exterior orientation elements accurately when carrying out geometric positioning based on geometric imaging model. Currently, least-squares method is widely adopted for the estimation of exterior orientation elements. However, in the absence of sufficient ground control points, least-squares estimation is not convergent. Therefore, we proposed a Bayesian estimation model for inversing exterior orientation elements in case of insufficient ground control points. In this study, according to scanning imaging mechanism, a geometric imaging model of geostationary satellites was established. A detailed theoretical inference of Bayesian estimation was then carried out from the geometry imaging model. A simulation experiment was finally conducted using randomly simulated ground control points. The experimental results showed that, in case of few ground control points, Bayesian estimation could also get accurate exterior orientation elements and had good positioning accuracy as well.