附加视线向量修正的卫星影像区域网平差

针对传统有理函数模型(RFM)区域网平差方法局限于姿态和轨道测量误差小、相机视场角小及影像交会角良好的情况,提出了附加视线向量修正的卫星影像区域网平差方法。首先利用影像附带的有理多项式系数(RPC)计算出像元视线向量,其次根据该视线向量恢复成像时刻虚拟位置和姿态信息,然后对恢复的虚拟位置和姿态构建误差补偿模型,最后通过最小二乘方法整体解算模型参数和连接点物方坐标。该方法从系统误差产生的原因构建补偿模型,可以规避传统区域网平差方法的近似假设和条件限制。通过对模拟数据以及多套测绘卫星和非测绘卫星数据进行试验的结果表明,该方法处理大姿态角误差、大视场角以及弱交会角等各种严苛条件下的卫星影像能达到比传统方法更好的效果。

Block adjustment of satellite imagery with line-of-sight vector rectification

Considering the traditional bundle block adjustment of rational function model is highly constrained by small error of attitude and orbit, narrow field camera and good image intersection angle, a block adjustment method of satellite imagery based on line-of-sight vector rectification was presented. Firstly, the light ray of an image point is calculated by using the rational polynomial coefficients attached to the image, and then the pseudo orbit and attitude of sensor is restored when the point was acquired, then an error compensation model is constructed for the virtual orbit and attitude, and finally the model parameters and object coordinates of tie points are solved simultaneously by the least square method. As the compensation model is modelled from the reason of system errors, it can avoid approximation assumptions and constraints of traditional strategy. Several comparative experiments of simulation data, mapping satellite and non-mapping satellite data are designed. The results show that this algorithm can achieve higher accuracy than the traditional method under various severe conditions such as images with large attitude angle error, large field angle and weak intersection angle.