基于GPS/BDS组合系统实现航测无人机动态定位

Aerial UAV kinematic positioning using combined GPS/BDS system

由于定位定向系统(POS)可直接获取航摄像片线元素与角元素,减少航测内外业工作量,提高航测作业的效率,无人机摄影测量已成为航空摄影测量的重要方式.常规实时动态(RTK)产品重量较大,难以应用于荷载有限的微小型无人机的POS系统.本文基于Doppler值修正伪距观测量,并联合平滑伪距与相位观测量实现无人机动态后处理定位(PPK).实测数据结果表明,较之单系统,全球定位系统/北斗卫星导航系统(GPS/BDS)组合系统可充分满足无人机动态定位的精度需求,结合平滑伪距与相位观测量可改善PPK定位的精度与可靠性.

Position and orientation system(POS)can acquire the line and angle elements of the aerial photographs directly,which can reduce the workload of unmanned aerial vehicle photogrammetry and improve work efficiency,thus the UAV photogrammetry has become an important way of data acquisition in aerial photogrammetry.For the large quality of conventional RTK products,it is difficult to be applied in the UAV surveying.In this paper,Doppler smoothing algorithm has been adopted to refine code observables,and then the combined Doppler-smoothed code(DSC)and phase data have been used to realize UAV post processed kinematic positioning(PPK).The results of measured data have shown that,compared with single satellite system,the combined GPS/BDS system can meet the requirement of kinematic positioning for UAV photogrammetry,and the efficiency and reliability of PPK positioning can be improved based on the DSC and phase observables.