There are currently five public NTP servers available from the Internet that has our hydrogen based master clock as their time-reference:
Time1.Stupi.SE 126.96.36.199, Time2.Stupi.SE 188.8.131.52, Time4.Stupi.SE 184.108.40.206, Time20.Stupi.SE 220.127.116.11
For IPv6 users, we have two NTP servers: Time4.Stupi.SE, 2001:440:1880:1007::153 and Time20.Stupi.SE, 2001:440:1880:1000::20
Finally we have a DNS entry "NTP.Stupi.SE" that will return one of the active servers that has our masterclock as timebase.
Clock ensemble to keep the local timescale @ Stupi. We produce a local timescale by combining relative measurements between each clock and the physical representation of the timescale generated by an AOG using one of our masers as it's frequency source. The timescale process receives data from other clocks in Sweden on a daily basis, and every month we also receive data from all other clocks contributing to TAI. We steer towards the BIPM data to be as close to UTC as possible, but the current time is always a prediction based on available clock information from local clocks. The Stupi clock ensemble consists of three active hydrogen masers and ten cesium clocks.
Clocks and timescale at Stupi is recognized by the Swedish Government as a national resource and participate as one of the three timing laboratories (together with SP and Onsala) to provide a resilient national timescale for Sweden. Support for external organizations can be provided on a case-by-case basis, contakt staff for more information.
This graph shows the difference in time between UTC and the local timescale at Stupi for the last 365 days. Vertical scale is in nanoseconds and horizontal scale is days in modified Julian date. This picture is produced by SP in Borås. (A nanosecond is 0.000000001 second)
Here is the difference between UTC(SP) in Boras and the local timescale at Stupi for the lastest 365 days.
We also have a alternate masterclock for backup. Here is it's data for the last 365 days.
More information on the performance of the induvidual clocks at Stupi is generously made available by SP at their clock measurement site.
Some of the clocks provide operational data telemetry information, here is the realtime data avaliable from our clocks..
NTP services and time transfer is a joint research project between Stupi AB and the Swedish National Testing & Research Institute SP and Everyware Mikrodata AB.
The project was co-sponsored by KK-Stiftelsen and PTS.
For additional info contact ti me@st upi.se