Relativistic geodesy article
The Independent web site has an interesting article on relativistic geodesy titles:
“Gravity measured for first time using a portable ‘atomic clock’”
The article on which the article was based is available in full here:
That would be a great tool for NGS if they can take it another order of magnitude.
As I read the article, they are saying that if they rebuilt their equipment using the very best techniques they have identified to control every variation, they think they could achieve 10 cm elevation uncertainty.
Levels by clock, where do I buy one?
Did you notice the size of their equipment? That and the fact that it is cutting edge research means you won't see it marketed for quite some time.
Give it a few years, they will come out with a phone app. ?