[rollei_list] Re: ...was Avedon OT Time
- From: "Allan Derickson" <alland435@xxxxxxxxxxx>
- To: <rollei_list@xxxxxxxxxxxxx>
- Date: Mon, 20 Dec 2010 19:26:56 -0800
Forty-some years ago I was an operator in an electronic monitoring station
in a remote area of the world. Our mission was to detect nuclear events to
check compliance with the nuclear test ban treaty and to find out who else
got nuclear weapon technology. It was very top secret at the time but has
been unclassified now.
This was before GPS and satellite monitoring and involved several different
technologies to detect the unique signature of a nuclear explosion. It was
critical that we knew the precise time at our station and all the other
stations to pinpoint the location of the detonation.
Every few months a two-man team would fly out with a cesium beam clock which
had been calibrated at the National Bureau of Standards. They would buy a
ticket for a seat on the plane for the clock. Our clock at the station had
some lesser technology but was still extremely accurate. It would be synced
with the cesium beam clock. I remember being impressed with the value of the
traveling clock and the care given it.
Allan
Eric:
Wikipedia is right about the Cesium 133 clocks is establishing
the time standard yet since the UTC is the time standard for the world
and it is still based on Cesium 133 clocks and then it is valid the
second definition from 1967 based on Cesium 133. Strontium and other
elements clocks are more exact than the clocks based on Cesium 133,
however this fact has sterted to be demonstrated a few years ago and
it will still take a long time before these clock become and
international standard, they are useful for some specific purposes but
regarding the universal and general time measurement Cesiem 133 is
still the rule.
BTW, Wikipedia is a great tool IMO.-
Carlos
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