Apparatus for time synchronizing based on common view of multiple satellites and filtering and method thereof

Abstract

The invention belongs to the technical field of satellite navigation, and in particular relates to an apparatus for time synchronizing based on multi-satellite common view and a [alpha]-[beta] filtering and a method thereof. The apparatus includes connected time synchronous modules which are mounted inside two pseudo satellites, wherein the time synchronous module includes: a multi-channel receiver module, a communication module, an information processing and clock correcting module. The method includes: through collection data of the two pseudo satellites, obtaining the position of the satellite tested and pseudo ranges with respect to the pseudo satellites A and B, obtaining an elevation angle of the satellite through calculation, and conducting weighting and averaging with the sine value of the elevation angle as the weight, conducting the [alpha]-[beta] filtering in combination with the mathematical model for clock error, further correcting clock errors, eventually obtaining a more accurate clock error estimation value, correcting the clock error of the pseudo satellite which needs synchronization based on the clock error estimation value, and at last achieving the time synchronization between the two pseudo satellites. The embodiments of the invention can eliminate random error in observed quantity, increase precision of time synchronization, and have a stronger ability than single channel common-view time synchronization method in terms of anti-interference.

Description

technical field [0001] The invention belongs to the technical field of satellite navigation, and in particular relates to a time synchronization device and method based on multi-satellite common viewing and α-β filtering. Background technique [0002] At present, the world's navigation satellite systems mainly include the GPS of the United States, the GLONASS of Russia, the GALILEO system under construction of the European Union, and the BD-2 satellite navigation system of our country. In addition, different departments and organizations in many countries and regions have also established their own satellite-based augmentation systems (SBAS), typically including EGNOS, OmniSTAR, QZSS systems, etc. It is foreseeable that the future will be a multi-system integration Global Navigation Satellite System (GNSS )era. However, the accuracy, reliability and availability of various global navigation satellite systems depend to a certain extent on the number and geometric distributio...

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Problems solved by technology

Among them, GNSS one-way time synchronization is restricted by various factors such as ionospheric delay, tropospheric delay, satellite ephemeris, clock difference, etc., the time synchronization accuracy is about 20-30ns, and the synchronization accuracy is poor, which cannot be used in real systems; The common view time synchronization method only realizes time synchronization between stations by observing one satellite at the same time. Since the signal propagation paths of the same satellite observed by two stations are not exactly the same, the time synchronization accuracy between stations is about 10-15ns; two-way ranging time synchronization uses channel The symmetry of the system greatly eliminates the common error, and the accuracy can reach 1ns, but the two pseudolite stations must be visible, and they are easily blocked by mountains and tall buildings on the ground and cannot be used; the optical fiber time synchronization method uses optical fiber to transmit time synchronization signals. The time synchronization accuracy can reach up to 200ps, but the cost of laying optical fibers over long distances is too high, and it is extremely vulnerable to damage

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