The issue of navigation using binary pulsars is investigated in this paper.We show how the effect of the binary motion is incorporated in the navigation measurement equation.Necessary reference systems and time scales...The issue of navigation using binary pulsars is investigated in this paper.We show how the effect of the binary motion is incorporated in the navigation measurement equation.Necessary reference systems and time scales are introduced and the transformation between different time scales is derived.Based mainly on Damour and Deruelle's binary model and the TEMPO2 software,the timing model resolving the time delay from emission to arrival is established with the solar system,interstellar and binary system delays included,which retains all the terms exceeding 1 ns.The navigation measurement equation is thus built and the parameters needed are listed.A comparison is made between Sheikh's measurement equation and that in this paper.It is found that it is not necessary to introduce a fictitious SSB arrival time as Sheikh does.Near-Earth navigation for the Keplerian orbit in the case of observing one pulsar is investigated.The uncertainties of the orbit parameters are derived using the least square fitting method,which reveals that observing one pulsar enables one to navigate near-Earth spacecraft.展开更多
As the scientific data volume in deep-space exploration rapidly grows,spacecraft heavily relies on high data-rate signals that span several megahertz to transmit data back to Earth.Employing high data-rate signals for...As the scientific data volume in deep-space exploration rapidly grows,spacecraft heavily relies on high data-rate signals that span several megahertz to transmit data back to Earth.Employing high data-rate signals for high-accuracy radiometric interferometry can simultaneously deal with data transmission and spacecraft navigation.We demonstrate very long baseline interferometry(VLBI)tracking of the Chang’E-3 lander and rover to determine their relative lunar-surface position using downlink high data-rate signals.A new method based on the VLBI phase-referencing technique is proposed to obtain the differential phase delay,which is much more accurate than the differential group delay acquired by conventional VLBI approaches.The systemic errors among different signal channels have been well calibrated using the new method.The data from the Chang’E-3mission were then processed,and meter-level accuracy positions of the rover with respect to the lander have been obtained.This demonstration shows the feasibility of high-accuracy radiometric interferometry using high data-rate signals.The method proposed in this paper can also be applied to future deep-space navigation.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 41074023)
文摘The issue of navigation using binary pulsars is investigated in this paper.We show how the effect of the binary motion is incorporated in the navigation measurement equation.Necessary reference systems and time scales are introduced and the transformation between different time scales is derived.Based mainly on Damour and Deruelle's binary model and the TEMPO2 software,the timing model resolving the time delay from emission to arrival is established with the solar system,interstellar and binary system delays included,which retains all the terms exceeding 1 ns.The navigation measurement equation is thus built and the parameters needed are listed.A comparison is made between Sheikh's measurement equation and that in this paper.It is found that it is not necessary to introduce a fictitious SSB arrival time as Sheikh does.Near-Earth navigation for the Keplerian orbit in the case of observing one pulsar is investigated.The uncertainties of the orbit parameters are derived using the least square fitting method,which reveals that observing one pulsar enables one to navigate near-Earth spacecraft.
基金supported by the Key Techniques Research Program of China’s Lunar Exploration(Grant No.TY3Q20100009)
文摘As the scientific data volume in deep-space exploration rapidly grows,spacecraft heavily relies on high data-rate signals that span several megahertz to transmit data back to Earth.Employing high data-rate signals for high-accuracy radiometric interferometry can simultaneously deal with data transmission and spacecraft navigation.We demonstrate very long baseline interferometry(VLBI)tracking of the Chang’E-3 lander and rover to determine their relative lunar-surface position using downlink high data-rate signals.A new method based on the VLBI phase-referencing technique is proposed to obtain the differential phase delay,which is much more accurate than the differential group delay acquired by conventional VLBI approaches.The systemic errors among different signal channels have been well calibrated using the new method.The data from the Chang’E-3mission were then processed,and meter-level accuracy positions of the rover with respect to the lander have been obtained.This demonstration shows the feasibility of high-accuracy radiometric interferometry using high data-rate signals.The method proposed in this paper can also be applied to future deep-space navigation.
