The three corner hat measurement of three hydrogen masers in remote locations via fiber based frequency synchronization network

As the first step of Beijing regional time and frequency network, Currently, Tsinghua University (THU) and the Changping site of National Institute of Metrology (NIM-Changping) have been linked and synchronized via the fiber network. The frequency stability of the hydrogen maser in NIM and the ultra-stable crystal oscillator steered by a cesium atomic clock in THU was measured. More atomic clocks from the Beijing Institute of Radio Metrology and Measurements, Hepingli site of NIM and Peking University (PKU) will join the synchronization network soon, with these clocks we can get the stability of each clock though three-corner-hat method.