A Time Service Method in Deep Space Based on X-ray Pulsar

Abstract

The invention provides a deep-space time service method based on X-ray pulsars, carries out pulsar ground radio observation, determines the orientation and rotation parameters of the pulsar, obtains the pulsar timing model to predict the time when the pulse reaches the SSB; the detection on the satellite The pulsar is observed by the X-ray instrument, and the time when the photon arrives at the spacecraft is converted to the SSB, and the integrated pulse profile is folded at the SSB; the integrated pulse profile and the standard pulse profile are cross-correlated in the frequency domain to obtain the TOA, and the timing model Forecast the TOA difference to get the timing residual before fitting; fit the linear term to the timing residual before fitting to get the frequency deviation of the steered satellite-borne atomic clock; compensate the photon arrival time recorded by the reference satellite-borne atomic clock according to the frequency deviation After that, the measured TOA is obtained again, and the frequency control is completed. The invention can improve the frequency deviation of the satellite-borne clock and improve the accuracy of the satellite-borne clock.

Description

technical field [0001] The invention belongs to the technical field of X-ray pulsar deep space timing application, and relates to the establishment of an X-ray pulsar timing model and a method for correcting the frequency deviation of an on-board atomic clock by using a pulsar with a highly stable rotation. Background technique [0002] For most spacecraft that fly around the earth and perform PNT (navigation, positioning, timing) tasks, the accuracy of time is maintained by receiving the time signal of the earth satellite navigation system GNSS. This method needs to adjust the frequency of the satellite clock in advance according to the orbital altitude of the navigation satellite, and regularly compare the time with the ground station to correct the output time or speed of the atomic clock to keep it consistent with the earth time TT. However, this time receiving method is only suitable for spacecraft flying in the near-Earth space on the earth's surface. For the wider sol...

AI Technical Summary

Problems solved by technology

For the spaceborne atomic clock, due to the instability of the output frequency of the frequency source and the change of the space magnetic field environment where the spacecraft is located, there will be a frequency deviation between its output frequency and the nominal frequency, which will affect the local accuracy of time

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