北斗系统是我国自主建设运行的全球卫星导航系统,很多人知道它能进行定位、导航,实际上,北斗系统还 有一项非常重要的功能,那就是卫星授时。 用户接收到北斗的广播信号后,自主修正本地时间与标准时间的时间差,就能实现时间同步。 有了北斗系统,意味着中国人更能将精准时间掌握在自己的手里。 当前,全球存在四种卫星授时系统,除了我国的北斗系统,还有美国的GPS系统、俄罗斯的GLONASS系 统、欧盟的伽利略系统。 北斗授时的精度,可以达到10纳秒量级。北斗导航卫星上配有星载原子钟,以确保北斗授时系统有精确的 时间源。 所谓"授时",即通过北斗卫星、短波、长波、低频时码、电话、网络等方式,把标准时间分发给通信、电 力、交通、测绘、航空航天、国防等诸多行业和部门。这些系统再根据接收到的信号,校准自身的时 钟。 ...

Group 1: Core Insights - A major cyber attack by the U.S. National Security Agency (NSA) targeting China's National Time Service Center has been uncovered, aiming to disrupt the integrity of "Beijing Time" [1] - The NSA's cyber operations have been systematic and planned, utilizing 42 specialized cyber attack tools from August 2023 to June 2024 to launch high-intensity attacks on multiple internal network systems of the National Time Service Center [1] - The attacks are primarily conducted during late night to early morning Beijing time, employing virtual private servers from various global locations to obscure the source of the attacks [1] Group 2: Historical Context of the National Time Service Center - The National Time Service Center, located in Xi'an, Shaanxi, is responsible for broadcasting "Beijing Time," which has historical significance dating back to its first broadcast in 1949 [2][4] - The establishment of the time service station in Shaanxi was strategically chosen for its central location in China, ensuring nationwide signal coverage and security [4][5] Group 3: Technological Advancements in Timekeeping - The precision of timekeeping in China has significantly improved, with the National Time Service Center achieving a remarkable accuracy of 60 million years without a second of error starting in 2024 [7] - The center utilizes atomic clocks, specifically cesium fountain clocks, which have been developed to provide a stable and precise standard time [6][7] Group 4: Implications of Cyber Attacks on Timekeeping - Disruption of "Beijing Time" could have severe consequences across various sectors, including power, finance, and communication, with even minor time discrepancies leading to significant operational failures [9] - The U.S. aims to undermine China's technological and economic development by targeting the foundational time standards that support critical infrastructure [9] Group 5: Role of the BeiDou System - The BeiDou satellite navigation system not only provides positioning and navigation but also plays a crucial role in timekeeping, offering high precision time synchronization capabilities [11][12] - The BeiDou system enhances China's ability to maintain control over its time standards, ensuring that accurate timekeeping is domestically managed [13]