[LEAPSECS] LEAPSECS Digest, Vol 51, Issue 22

[Tony Finch]

On Mon, 7 Feb 2011, Steve Allen wrote:

>

> Until there is an ensemble of cesium chronometers not on the surface of

> the earth there is no easy way to measure the potential depth to 1e-10,

> so the corrections currently being used to compensate for the NIST and

> PTB chronometers being about a mile high are as good as things can get.


The PTB campus is at about 75m above sea level.

Also, doesn't the GPS count as an ensemble of atomic clocks?

Tony.
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