Measuring procedure for Fermi Normal coordinates

[PAllen]

Locally, Fermi normal coordinates are designed to correspond with direct measurement of distances (born rigidity). I also discovered that Synge's book on GR establishes that very locally, radar distance must match Fermi normal distance, but not in general (obviously). What I am wondering is whether there is any conceivable procedure for measuring Fermi normal distance, say at solar system scale? I can't come up with anything other than: if you know the local metric in detail, and track your own acceleration, you can, in principle, convert from a radar ranging distance to a Fermi-normal distance. That is not very practical. Any operational way to do this?

 

[pervect]

The only other thing that comes to mind is a large number of observers, all of whom are stationary with respect to you (you can use the radar notion of stationary), and using a "chain of observers" in a straight line to measure the distance. That's really more a conceptual appraoch than something you'd carry out in practice, though.

Knowing the local metric in detail is probably the most practical.