GPS多普勒差分测速算法

全球卫星定位系统(GPS)多普勒单点测速技术是单GPS天线测姿技术的核心，但其测速精度易受卫星速度误差、卫星钟漂、电离层延迟、对流层延迟以及飞行器位置误差等因素的影响。针对上述问题，提出结合GPS地面基准站卫导观测数据，对机载GPS多普勒观测量进行双差处理，从而得到GPS多普勒双差方程。求解该双差方程，能够有效缓解上述不利因素的影响，得到精度更好的飞行器实时速度。半实物仿真计算结果与跑车实验计算结果都表明多普勒差分测速精度大幅优于多普勒单点测速精度。

A velocity determination algorithm via difference GPS Doppler measurements

The Global Positioning System(GPS) Doppler single-point velocity determination algorithm is the core of the single-antenna GPS attitude determination technology.However the velocity estimation accuracy of the above algorithm is affected by satellite velocity errors,satellite clock drifts,ionospheric delays,atmospheric delays,and aircraft location errors,etc.For these problems,the aircraft GPS Doppler observations are double-difference processed by combining the GPS observations of the ground reference station,and thereby the GPS Doppler double difference equation is obtained.By solving this equation,the above-mentioned adverse factors can be mitigated,and a more accurate real time velocity of the aircraft can be obtained.The computation results of the semi-physical simulation and the dynamic car test indicate that the velocity estimation accuracy of the suggested GPS Doppler double difference velocity determination algorithm is more precise than that of the GPS Doppler single-point velocity determination algorithm.