GNSS载波多普勒频移计算、分析及实验验证

Calculation, Analysis and Experimental Verification of GNSS Carrier Doppler Frequency Shift

摘要:

全球卫星导航系统信号处理中,多普勒频移至关重要;文章对地心惯性坐标系下载波多普勒频移最大值计算进行了研究,其推导中没有考虑地球自转速度和地面用户位置的影响;文章针对这个问题进行分析,通过建立卫星和用户位置和速度之间的立体几何模型,提出了地心地固坐标系下任意用户位置载波多普勒频移最大值的精确计算方法;同时针对多普勒频移计算问题,通过构建卫星与用户之间的距离向量,提出了基于精密星历的任意用户位置载波多普勒频移计算方法;最后使用GNSS仿真数据和实测数据进行验证,两种方法的计算结果均和实验结果相符合;两种新方法能够解决地心地固坐标系下特定位置处的多普勒频移最大值和特定位置处载波多普勒频移的计算问题。

Abstract:

The Doppler frequency shift is crucial in Global Satellite Navigation System signal processing. This paper studied the calculation of the maximum Doppler frequency shift in Earth-Centered Inertial Coordinate System, its derivation didn’t consider the impact of the Earth's rotation rate and user location. This issue was analyzed in this paper, through establishing three-dimensional geometric model of the location and speed between the satellite and the user, proposed a computational method of Doppler frequency maximum shift at any user’s location in Earth-Centered Earth-Fixed Coordinate System. Simultaneously, for the calculation of the Doppler frequency shift, proposed a computational method of Doppler frequency shift at any user’s location based on the precise ephemeris by constructing the distance vector between the satellite and the user. Finally, GNSS simulation data and the real data are used to verify, the results of two methods are consistent with the experimental results. Two new methods can compute Doppler frequency shift maximum and Doppler frequency shift at any user’s location in Earth-Centered Earth-Fixed Coordinate System. 