Accurate synchronization system with combination of GPS and constant-temperature crystal

Abstract

The invention discloses an accurate synchronization system with combination of a GPS and a constant-temperature crystal. The accurate synchronization system comprises a GPS receiving module, a frequency calibration and correction circuit, a constant temperature crystal oscillator and a synchronization trigger signal generating circuit, wherein the GPS receiving module is used for receiving a time signal of a positioning satellite so as to output a pulse per second signal (PPS) for accurate synchronization; the constant-temperature crystal oscillator is used for generating a stable frequency output signal; the frequency calibration and correction circuit calibrates and corrects the output frequency of the constant-temperature crystal oscillator by using the PPS; and when the GPS works normally, the synchronization trigger signal generating circuit generates an accurate synchronization trigger signal by using the PPS, and when the GPS works abnormally, the synchronization trigger signal generating circuit generates the accurate synchronization trigger signal by using the corrected output frequency of the constant-temperature crystal oscillator. Therefore, the combination synchronization system can work normally under any environment condition.

Description

Technical field [0001] The invention relates to a precise synchronization system combining GPS and constant temperature crystals, which is particularly suitable for synchronous geophysical exploration in mountainous areas or forest-covered areas. Background technique [0002] At present, the commonly used synchronization techniques include GPS synchronization and oven-controlled crystal oscillator synchronization. GPS synchronization uses the pulse-per-second signal (PPS) output by GPS to be accurately synchronized with UTC to synchronize various working systems. Its advantages are high synchronization accuracy and no synchronization error accumulation. The disadvantage is: GPS is easily blocked by terrain and ground objects, which makes synchronization invalid. For the synchronization of the Oven Crystal Oscillator, due to frequency drift and nominal frequency error, there is a problem of accumulation of synchronization errors. In order to solve this problem, it is necessary to...

AI Technical Summary

Problems solved by technology

The disadvantage is: GPS is easily blocked by terrain and objects, which makes the synchronization invalid

For the synchronization of constant temperature crystal oscillators, due to frequency drift and nominal frequency errors, there is a problem of accumulation of synchronization errors. In order to solve this problem, it is necessary to frequently check the clock, which causes inconvenience to the synchronization work.

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