Research On Orbit Determination For Formation Satellite Based On Pulsar

In recent years,formation satellite is a new research area and has received much attention.The realization of formation satellite function depends on the precise formation states determination,which includes absolute and relative orbits,attitudes and clock biases separately.Currently,GPS is a chief means for the states determination of formation satellite,including pseudorange measurement and carrier phase measurement.However,for high orbit and deep space missions,the determination of formation satellite state can’t be realized because of the restriction of the number of observable GPS satellite.From the strategic significance to consider,it is not a navigation and positioning system which our country can rely on for the United States keep controlling the GPS system.Recently,XPNAV(X-ray Pulsar-based Navigation)become a potential replacement for GPS space navigation.This paper focus on the formation satellite orbit determination method,including absolute orbit determination and relative orbit determination.When the formation satellite as a whole rotates around the earth,X-ray pulsars’ TDOA was used to achieve absolute orbit determination and restrain the overall drift.Relative orbit is the premise and foundation for formation design and control.The use of differential pulsar’measurements can achieve relative orbit determination for formation satellite.The simulation results demonstrated that the feasibility of pulsar navigation system.Once the inter-satellite communication links subject to interference or interruption,each satellite can switch to a single satellite navigation mode to continue working,improving the system’s fault tolerance.