地心直角坐标系下的航摄光学影像严密定位模型

Rigorous Positioning with Airborne Optical Images in ECEF

对地心直角坐标系(Earth-centered Earth-fixed,ECEF)中航空光学影像几何定位模型的应用潜力及难点进行了分析,提出了四元数初始姿态与欧拉补偿偏置角相结合的严密定位模型,避开了单独使用四元数时姿态参数去相关性、高频变化姿态精化模型表达,以及姿态与其他观测值联合平差等方面存在的困难,克服了单独使用欧拉角姿态时可能存在的奇异、多解等不足,能够吸收已有成熟的定位定姿系统(position and orientation system,POS)辅助光束法平差方法,实现了ECEF下航摄光学影像的严密定位。利用航空框幅式影像和三线阵影像进行了实验,证明了模型和方法的可行性。本文模型不受影像地理覆盖范围的限制,能为ECEF中包含航空光学影像在内的多源遥感数据的联合处理提供参考。

In this paper, application potentiality and the difficulties of geometric positioning in Earth- centered Earth-fixed coordinate systems （ECEF） with airborne optical images are analyzed. A rigorous sensor model, which is based on initialization quaternion attitudes and refinement Euler bias angles, is presented. Compared to those models only with quaternion parameters, the proposed model can avoid the difficulties in the decorrelation of attitude parameters, in the refinement model for irregular changing attitudes, and in combined adjustment with attitude angles and other observed values. While comparable to those other models only in the Euler parameters, our model overcomes the problem of multiple solutions and possible singularity. The proposed model exploits existing mature methods found in traditional pOS-supported bundle block adjustment to realize rigorous positioning in ECEF with airborne optical images. Tests using frame and three line sensor （TLS） images show that our model is effective and is not restricted by the range of image coverage. It can provide a reference for multiple image positioning including airborne optical images.