Implementation of Synchronous Clock based on the Coal Mine Exploration Radar

Abstract

To make a high precision synchronization in transmitter and receiver when the coal mine exploration radar work in the field survey, this paper has designed a high precision synchronous clock based on complementary coordinate GPS and OCXO. The clock phase splitting algorithm is used to measure GPS output time difference between stable second pulse signal (1PPS) and local second pulse signal, and then the Kalman filtering algorithm is used to filtering time lag to get the frequency deviation controlling quantity of OCXO, eventually making high precision synchronization between stable 1PPS and local second pulse signal. The experimental results show that synchronous clock can work long time until GPS is valid, the synchronization precision of transmitter and receiver is better than 150ns. It can take local second pulse instead of stable second pulse signal (1PPS), in the case of one or two GPS receiver are invalid. The operational time of synchronous clock is more than half an hour.