International Clock and Oscillator Networking - ICON

时间是量，它可以被测量到所有计量中最高的精度。我们在日常生活中都受益于这种非凡的精度，因为精确的时间使超高速宽带通信中的数据包同步，并通过计算卫星导航中射频信号的飞行时间精确到纳秒来确定我们的位置。这些具有重要经济意义的应用依赖于微波原子钟，其商业形式的精确度达到十分之一。由于光学时钟和可获得的光学频率计数方法的发明，我们目前面临着一场计时精度的革命，这一点已经得到2005年诺贝尔物理学奖的认可。这些新颖的时钟已经达到了超过1/10^18的稳定性，比最先进的水平高出4个数量级以上。然而，在时钟技术快速进步的同时，如何将这样的精度以实用和高效的方式转移到用户社区，仍然有很多需要学习的地方。微波链路，例如用于当前卫星时间传输的微波链路，对于这种精度来说是不现实的缓慢，而光纤链路需要昂贵的专用光纤连接，并且限于几个100公里，使得洲际连接不切实际。此外，在10^-18的精度下，重力与频率耦合的广义相对论等效应正在发挥作用，并使转移依赖于大陆板块在固体潮和更大的降雨量中的变形。ICON汇聚了世界领先的可移动光时钟和世界领先的光链路空间基础设施，探索精确时间传递的极限。包括利用世界领先的原子芯片概念制造更紧凑、更坚固的便携式时钟，我们的目标是为每个人带来精确的时间-首先是依靠精密振荡器的研究人员，然后是商业应用，造福于更广泛的社会。

Time is the quantity, which can be measured to the highest precision of all metrological quantities. We all benefit from this extraordinary precision in our everyday lives, as precision time enables synchronization of data packets in ultrafast broadband communication and the determination of our position by computing the flight times of radiofrequency signals in Satellite Navigation to nanosecond precision. These economically important applications rely on microwave atomic clocks, which in their commercial form are precise to 1 part in 10^14. We are currently facing a revolution in timing accuracy due to the invention of optical clocks and accessible ways of counting optical frequencies, which has already been recognised by the Nobel Price in Physics in 2005. These novel clocks already reach stabilities beyond 1 part in 10^18, more than 4 orders of magnitude beyond the state-of-the art. However, while the clock technology is progressing rapidly, there is still a lot to learn about how such a precision can be transferred to the user community in a practical and efficient way. Microwave links, such as used in current satellite time transfers, are impractically slow for such precision, while optical fibre links need expensive dedicated fibre connections and are limited to a few 100 km, making intercontinental connections impractical. In addition, at 10^-18 precision, effects such as general relativity coupling gravity to frequency are coming into play and make the transfer dependent on deformation of the continental plates in Earth tides and larger rain falls. ICON brings together world leading transportable optical clocks and world leading optical link space infrastructure to explore the limits of precision time transfer. Including work on making transportable clocks more compact and robust with world-leading atom chip concepts, we are aiming at bringing precision time to everyone - first researchers relying on precision oscillators and later in commercial applications for the benefit of wider society.