China’s NIM: BIPM GNSS time transfer standard calibrated in China for BeiDou for the first time — technical parameters of the BeiDou-3 B1C and B2a signals measured
On 29 September 2026 the Guangming Daily reported, citing China’s National Institute of Metrology (NIM), that the GNSS time transfer standard of the International Bureau of Weights and Measures (BIPM) had for the first time completed calibration and comparison verification of key BeiDou parameters in China. NIM published the text on its website on 9 October.
- NIM precisely determined the technical parameters of two BeiDou-3 signal frequencies — B1C and B2a — which according to the institute lays the foundation for users worldwide to obtain “standard time” via BeiDou. The calibration relied on the national time and frequency standard; the team tackled problems such as precise delay measurement, antenna phase centre calibration and uncertainty evaluation.
- The universal standard time is UTC. More than 80 time and frequency laboratories take part in the BIPM’s international atomic time cooperation, comparing more than 400 atomic clocks mainly by GNSS time transfer; UTC is produced after weighted averaging, frequency calibration and leap-second adjustment. The BIPM publishes each laboratory’s deviation from UTC monthly, and countries adjust their local time accordingly.
- After the calibration, the BIPM is to use the standard to gradually calibrate the links of important G1-level laboratories. According to the BIPM guidelines for GNSS equipment calibration, the time transfer equipment of “Group 1” laboratories in the regional metrology organisations is calibrated by the BIPM, while other laboratories (Group 2) are calibrated in campaigns organised by the regional organisations, with reference to Group 1 systems.
- According to the article, BeiDou-3 has fully taken over the system’s main services, and with further development of time transfer link calibration, monitoring and assessment and the mutual recognition system it is to provide more accurate and reliable timing services to users worldwide.
Source: 中国计量科学研究院 (NIM) — 《光明日报》：“北斗时间”将成为全球高精度时间比对工具 (przedruk artykułu z 29.09.2026; 9.10.2026)