bpm shortwave multi-frequency point timing system

Abstract

The invention provides a BPM short-wave multi-frequency point timing system. A channel selection unit receives four frequency point time service signals transmitted by a BPM time service station, andconverts each frequency point time service signal into a fixed carrier frequency point 2.5 MHz digital signal; a demodulating search unit performs demodulation and low-pass filtering on the received digital signals, performs four-path folded matching correlation on an obtained orthogonal time signal and a local 1 KHz orthogonal time signal, utilizes a correlation value and a threshold value to detect two correlation peaks to obtain positions of maximum values of the two correlation peaks, and transmits the positions to a timing output module; and the timing output module identifies a UTC second time signal and a UTC minute time signal, filters the UTC second time signal to prevent misjudgment, and synchronizes local second and minute signals. The BPM short-wave multi-frequency point timingsystem adopts an all-digital receiving mode, can receive the BPM short-wave time service signal at any place, and has the advantages of multi-frequency-point reception, high degree of automation, high timing precision, full digitization and the like.

Description

technical field [0001] The invention relates to a timing system, which belongs to the technical field of radio time service and timing. Background technique [0002] As one of the large scientific devices, the BPM short-wave timing system is undertaken by the National Timing Center of the Chinese Academy of Sciences. It transmits time signals through one or more reflections of the ionosphere, which can cover my country's land and offshore waters. It has the advantages of wide range, simple transmitting equipment, and low receiving cost. Its main function is to perform timing and frequency calibration, and it is also used in communication, radio wave propagation, meteorology and ionosphere and other related scientific research. [0003] The BPM short-wave time service system alternately broadcasts standard time and standard frequency signals at four frequencies (2.5MHz±5KHz, 5MHz±5KHz, 10MHz±5KHz, 15MHz±10KHz) every day, and broadcasts the Coordinated Universal Time UTC time ...

AI Technical Summary

Problems solved by technology

Summarizing the existing BPM timing terminals, there are problems such as low degree of automation, low efficiency of time signal detection, low degree of digitization, manual selection of receiving frequency points and adjustment of signal gain, etc.

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