Stable output method for PPS (pulse per second) of satellite navigation receiver

Abstract

The invention discloses a stable output method for the PPS (pulse per second) of a satellite navigation receiver, and the method comprises the steps that an FPGA maintains a local PPS according to thefrequency of a local rubidium atomic clock and records the PPS outputted by a general satellite navigation receiver, and a TDC measures the time interval between the PPS outputted by the receiver andthe local PPS; the FPGA transmits a measurement result to a DSP, and the DSP carries out the limited memory Kalman filtering, estimates the position of an ideal second in real time and outputs the parameter of the ideal second through a numerical control delay line, wherein the position of the ideal second is converted into a control parameter of the numerical control delay line in the DSP; the FPGA outputs configuration parameters according to the parameter of the ideal second, adjusts the final second output through the numerical control delay line, and completes the stabilizing of the PPS.The structure of a system is easier to implement, is suitable for a general receiver, and is lower in cost. The output precision of the PPS is higher than 3ns (RMS) through testing after 6h synchronization. The method employs the limited memory Kalman filter, and effectively inhibits the system diffusion caused by the non-gaussianity of a model.

Description

technical field [0001] The invention belongs to the technical field of atomic clocks and time-frequency, and in particular relates to a method for outputting second pulses of a general satellite navigation receiver, which is used to improve the stability of the output second pulses of the receiver. Background technique [0002] While providing navigation and positioning, the satellite navigation system also provides a high-precision timing means. The timing methods based on satellite navigation can be roughly divided into one-way timing, common-view time transfer and satellite two-way time-frequency transfer. [0003] One-way timing refers to the method of observing one or more satellites at an observation station with known coordinates (or unknown coordinates but capable of receiving more than four satellites) to determine the clock deviation of the station. Its timing accuracy is mainly related to receiver error, satellite ephemeris error, satellite clock error, and atmos...

AI Technical Summary

Problems solved by technology

However, it can only provide a timing accuracy of 100ns under a certain confidence interval, which is difficult to meet the needs of high-precision application clocks

[0005] Common-view time transfer and satellite two-way time-frequency transfer can provide high timing accuracy, but it essentially obtains the clock difference between the two stations, that is, time synchronization, mainly to achieve time comparison between a small number of users, and the cost is relatively high

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