航空推扫式外拼接成像系统子视场相对定向方法

Relative Orientation Method for Airborne Pushbroom Combined Imaging System

将多个阵列推扫式相机以阵列方向视场拼接的方式进行组合,可以克服相机的探测器规模限制,在保证空间分辨率的同时有效增加视场角。现有视场拼接方法多建立在各子视场严格几何定标的基础上,需要高精度地面定标场数据或检校航带支持。本文提出了一种基于同名特征的子视场相对定向方法,从窄重叠区同名像点出发,在数字高程模型的辅助下建立子视场相对定向模型,同时辅以视场外侧稀少控制点的绝对约束,准确恢复相邻相机之间的安装关系。利用仿真数据对该方法进行的验证实验表明,本文方法解算得到的相对定向参数可支持子视场影像的无缝拼接,影像拼接精度优于2 pixel,几何定位精度平面中误差优于3 pixel。

Combining multiple pushbroom cameras along the sampling direction can overcome the limitation of the detector scale,and effectively expands its field of view and improves the imaging efficiency.Existing stitching methods are based on strict geometric calibration of each sub-field,and strongly dependent on expensive calibration fields.This paper presents a relative orientation method of sub-field of view based on sparse ground control points.This method establishes a relative orientation model with tie points and digital elevation model.To ensure the stability of the solution,it is supplemented by the absolute constraints of the sparse control points.Relationship between adjacent cameras can be achieved by this method,and simulation data was used to verify the method.Results show that the relative orientation parameters can support seamless stitching of sub images.The accuracy of image stitching is better than 2 pixel,and the plane error of geometric positioning accuracy is better than 3 pixel.