JJY - Monitoring Data [transmitted]

The transmission stations at Otakadoya-yama (40kHz) and Hagane-yama (60kHz) broadcast standard time and frequency signals 24 hours a day. Notification No. 382 of the Ministry of Internal Affairs and Communications (1999) stipulates that the transmitted frequency signal shall have an uncertainty of one part in 10¹² or less. The time information is required to agree with international time to 1/100,000 of a second.

NICT continuously monitors the transmitted JJY signals, the results can be accessed from web pages as shown below. The character encoding is EUC-JP.

Deviation of standard frequency at transmission station

We publish here the frequency deviation of the standard frequency signals transmitted by the JJY stations. The reported value is a 24-hour average of the relative difference of the frequency reference at the transmission station from the frequency standards at NICT’s Koganei headquarters. It is determined by satellite-based time transfer.

After selecting the period and station, please click on “Show data”. The data will be shown in a new window. Each report covers one month.