无人机机载相机曝光时刻摄影中心三维坐标高精度插值算法研究

随着机载定位定向系统（POS）的不断完善,无人机技术已成为高精度摄影测量的重要途径．由于POS系统中全球卫星导航系统（GNSS）接收机的采样频率有限,需要对机载相机曝光点时刻摄影中心三维坐标进行插值计算．本文对常用的四种插值算法进行了研究,并通过实测数据对比不同插值算法的优劣,结果表明,当GNSS原始数据采样频率高于1 Hz时,三次样条插值算法误差均方根误差优于5 cm,更适用于无人机曝光时刻摄影中心三维坐标的高精度插值． 

Research on high precision interpolation algorithms for 3D coordinates of projection center of UAV at exposure time

With the continuous improvement of airborne POS system, UAV technology has become an important way of high precision photogrammetry. Because of the limited sampling interval of GNSS receiver in POS system, it is necessary to interpolate the three-dimensional coordinates of projection center of the airborne camera at the exposure time. Four interpolation algorithms have been studied in this paper and real measurements have been used to compare the merits and demerits of different interpolation algorithms. The results show that the root mean square error of cubic spline interpolation algorithm is better than 5 cm when the sampling interval of raw GNSS observations is more than 1 Hz, which means that cubic spline interpolation algorithm is more suitable for high-precision interpolation of three dimensional coordinates of projection center.