2008年9月发射的中国环境与灾害监测预报小卫星星座(简称HJ星座)A、B星配置的宽覆盖载荷,可广泛应用于生态环境和灾害的大范围动态监测和快速重访。针对传统的物理定位模型在CCD相机宽覆盖成像时难以达到较好的精度,尤其是在CCD线阵方向误差明显的问题,在考虑CCD相机畸变模型的情况下,提出一种基于一般多项式畸变模型的改进定位模型对影像进行几何定位。实验证明,影像在CCD线阵方向的误差能得到明显改善,该定位方法对于HJ-1卫星CCD影像几何定位精度的提高以及推广国产宽覆盖卫星影像的应用具有较大的意义。
Chinese small satellite constellation(abbreviated HJ constellation)is special for environment and disaster monitoring and forecasting.The satellites HJ-1A/B have the feature of wide coverage,which can be widely used in the ecological environment and disaster monitoring.The traditional positioning model can’t get ideal accuracy because of the CCD feature of wide coverage.It has significant error in CCD linear array direction.The reason is that the error factors changing with the field of view are not taken into count.Therefore,camera distortion model of CCD camera is considered and improved distortion model based on polynomial is used for image positioning in this thesis.The experimental results demonstrate the proposed algorithm improves the RMSE in CCD linear array direction is obviously reduced.The improved method has great significance to improve the positioning accuracy of HJ-1CCD image and promote the use of domestic wide coverage satellite images.