At 2 o'clock in the morning, Nanchang West EMU used the lights in a maintenance shed as if it were daytime. After confirming the permission, Cao Zhun, the head of the Nanchang West Vehicle Equipment Workshop at the Electric Service Section of China Railway Nanchang Bureau, and his colleagues climbed onto the roof of the high-speed train one after another to conduct a comprehensive "physical examination" of the Beidou antenna. Above the streamlined front of the car, a pair of "horns" stand quietly. Don't underestimate these two antennas, they are like a pair of sensitive 'ears' used to receive signals from the Beidou satellite. "Cao Zhun lowered his body, held a strong flashlight, and scanned every part of the antenna, checking for any possible' external injuries'. The Spring Festival travel rush has started, and trains are traveling north and south. After being hit by ice and snow, the antenna is prone to cracking or peeling off. Immediately, Cao Zhun took out a wireless intelligent tester to perform functional testing on the Beidou antenna. Although the tester may not look impressive, it can effectively 'capture' the 'dialogue' between the antenna and the satellite. He closely watched the time stream and signal waveform jumping on the instrument screen, adjusting the probe angle from time to time to ensure that the antenna was in the best condition. The quality of satellite signals received by the antenna directly determines the accuracy of train operation control. ”Cao Zhun told the Science and Technology Daily reporter that the train control system of the high-speed train is like the "brain" of train operation, and the onboard Beidou system can provide precise timing for the "brain". This is like setting a unified 'rhythm' for the 'brain', commanding the braking, traction and other systems of the high-speed train to work in sync and work together without delay. During the early stage of the Spring Festival travel rush, the Nanchang Electric Power Section upgraded more than 100 high-speed trains under its jurisdiction and fully replaced them with China's independently developed on-board Beidou system. The new system supports the 5G frequency band, with a 60% improvement in positioning accuracy. It can also automatically provide precise timing for various in vehicle devices, with an accuracy of up to 20 nanoseconds. Even if the train passes through mountains and tunnels, it can maintain its' sharp ears and clear eyes' and run more stably, "Cao Zhun's tone was filled with pride as he spoke. About 40 minutes later, the roof work is completed. Cao Zhun and his colleagues entered the cab of the high-speed train to inspect the train's overspeed protection system (ATP) equipment. The ATP will inform the driver in real-time about how fast the train should run and whether there are any bends ahead. ”As the core application terminal of the Beidou system, ATP can receive real-time wireless signals from the Beidou antenna and electromagnetic signals generated on the ground through devices such as speed sensors and vehicle responders, accurately calculate the current speed, position and other parameters of the moving vehicle, and provide precise "navigation" for the high-speed train at all times. Long term operation, ATP equipment will accumulate a large amount of 'cached data'. Cao Zhun opened the dedicated computer and skillfully updated data and cleared logs for him. As the simulation test starts, a series of green "normal" prompts light up continuously on the screen. In the past, relying on traditional GPS, it took two hours to repair a car. Nowadays, relying on the Beidou system, driving data can be transmitted in real-time to the backend analysis room, so we no longer have to run up and down with our devices, saving at least 25 minutes. ”Cao Zhun said. Every minute 'snatched' can make the train enter the next journey earlier and safer. During the Spring Festival travel rush, the railway department operates high-speed trains at night and adds popular line trains. The work area where Cao Zhun is located has to complete the inspection and maintenance of more than 50 high-speed train onboard equipment every day, almost doubling the workload compared to normal days. At 6am, as the last train maintenance was completed, Cao Zhun and his colleagues walked down the stairs one by one. Behind them, trains of finely inspected high-speed trains are gradually leaving the warehouse, heading towards various parts of the country towards the sunrise, guarding the safe return of thousands of passengers. (New Society)