Beidou and GPS dual system second time difference switching method

Abstract

A Beidou and GPS dual-system second time difference switching method, including a phase detector, is characterized in that: it also includes a time difference identification module and an intelligent control module; the phase detector is realized by a hardware platform FPGA, and measures the time of the Beidou system and the GPS The phase difference of the standard signal; the phase difference is sent to the time difference identification module for statistical analysis, and it is corrected; the analyzed identification difference is sent to the intelligent control module for switching process control. The high-precision phase detector in the present invention continuously performs phase discrimination on the local time scale and the Beidou system time scale, the local time scale and the GPS system time scale, and makes long-term statistics on the phase difference value to obtain an accurate phase difference value, and then slowly adjusts the time-frequency output , This method solves the problem of Beidou and GPS system integration very well, and obviously improves the overall timing performance of the product.

Description

technical field [0001] The invention relates to a time difference switching method, in particular to a second time difference switching method of Beidou and GPS dual systems. Background technique [0002] At present, satellite timing equipment under the GPS system is widely used in our country, but there are great potential safety hazards. The "Beidou-1" satellite navigation and positioning system is an all-weather, regional satellite navigation and positioning system independently developed by China. The three major functions of Beidou and GPS have appeared in the market, and there is a problem of switching between Beidou and GPS time scales in these products. The time scale signal of the Beidou system and the time scale signal of the GPS system At the same time, it is used as the tracking reference source of the local system, but the time scale signals of the Beidou system and the GPS system have systematic differences, and the delay error introduced by the unhealthy ephem...

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Problems solved by technology

[0002] At present, satellite timing equipment under the GPS system is widely used in our country, but there are great potential safety hazards. The "Beidou-1" satellite navigation and positioning system is an all-weather, regional satellite navigation and positioning system independently developed by China. The three major functions of Beidou and GPS have appeared in the market, and there is a problem of switching between Beidou and GPS time scales in these products. The time scale signal of the Beidou system and the time scale signal of the GPS system At the same time, it is used as the tracking reference source of the local system, but the time scale signals of the Beidou system and the GPS system have systematic differences, and the delay error introduced by the unhealthy ephemeris, the transmission attenuation of the wireless link, the multipath effect, and the external interference Both bit error and delay jitter will cause the drift of the satellite time scale signal. If the time scale phase difference between the Beidou and GPS systems cannot be accurately identified, or the switching strategy is improper, it will cause the local time scale signal to jitter, directly affecting the time service. The timing performance of the system has deteriorated. At present, there is a common defect in the switching strategy of this type of product. The time scale switching process of the dual system is too simple, there is no continuous statistics on the phase difference of the time scale signal of the dual system, and the switching process is also lacking. Considering the complex situation, even switching directly without considering the phase difference, resulting in reduced timing performance, the second signal switching method in this paper solves this problem very well

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