Design Of Networked Solution Algorithm For Space-borne GNSS

In order to maximize the utilization of limited transmit power and wireless spectrum,more communication satellites are adopting precise airground beamforming,which imposes strict requirements on satellite positioning and timing.In such an environment,high-performance spacebrne Global Navigation Satellite System(GNSS)receivers are particularly important.Compared with the traditional ground positioning on the ground,the spaceborne GNSS receiver moves rapidly in space together with the satellite,which makes the design of the corresponding positioning algorithm more difficult.This paper takes the integrated design of communication and navigation of the satellite Internet as the research background,and studies the high-precision networked solution technology of the GNSS navigation receiver of the core space-time reference acquisition unit on the satellite.The specific research contents include:1.A networked solution for spaceborne navigation receivers is proposed,which jointly utilizes multiple types of observations.This is a positioning algorithm for spaceborne navigation receiver with high accuracy and robustness,based on the filtering algorithm and orbital dynamics.Through differential transformation,the time difference and mechanical motion are separated,and then the motion state of the satellite is solved based on the deep orbital dynamics.The adverse effect of abnormal observation values on the positioning results can be detected and suppressed.Simulation results show that the algorithm can achieve submeter positioning accuracy.2.A ground passive tracking and positioning algorithm is proposed.The algorithm uses TDoA and FDoA observations for positioning and is used when available navigation satellite observations are missing.The position and velocity of the satellite are accurately solved by using the differential measurement information of multiple sites.The algorithm solves nonlinear systems of equations without iterative operations.Simulation results show that the algorithm can achieve meter-level positioning accuracy.3.Based on the GNSS test load of the TN-1A satellite of the "Smart Sky-Net" project,develop software codes and carry out on-orbit test verification.