相对定向的机载惯性测量装置视准轴误差求解方法

A Solving Method for the Boresight Misalignment of Airborne IMU Based on Relative Orientation

利用航摄像片存在的相对几何位置关系,将机载IMU视准轴误差引入立体像对相对定向模型中,提出一种基于相对定向的机载IMU视准轴误差求解新方法。详细推导了基于单个立体模型和连续立体模型求解IMU视准轴误差的数学模型,并用3组带有IMU设备获取的实际航空影像数据进行了试验验证。结果表明,所推导的机载IMU视准轴误差求解方法是正确、可行的,利用3张以上相邻像片构成的连续立体模型即可求解出IMU的视准轴误差,用其补偿IMU直接测定的外方位角元素,可以使对地目标定位结果得到较大的提高,该方法避免了野外布设检校场和其他地面控制条件带来的诸多问题,有利于带机载IMU的航空遥感快速对地目标定位。

The boresight misalignment of airborne inertial measurement unit(IMU)is introduced into relative orientation model of aerial stereo image pairs using the inherent relative geometric relationship between aerial images,and a novel method to solve the boresight misalignment of airborne IMU based on relative orientation is proposed.The mathematical models for solving the boresight misalignment of airborne IMU are derived in detail based on a single stereo model and multiple consecutive stereo models,respectively.Then,three sets of actual images obtained with IMU are tested.The empirical results show that the mathematical model established is correct and feasible.The boresight misalignment could be solved using multiple consecutive stereo models constituted by more than three adjacent aerial images,and the results of direct georeferencing can be improved significantly if using the solved boresight misalignment to compensate the exterior angle elements obtained by aerial IMU directly.The method proposed in this paper could avoid many problems brought about by setting calibration field and the other ground control conditions,and it is beneficial for direct and quick georeferencing when using aerial remote sensing equipment with airborne IMU.