Where Am I ?

[Dave Shaffer]

Pauli - RTK is basically radio interferometry, which is actually pretty straightforward (that's what paid my bills for 30 years as a radio astronomer). I did Very Long Baseline Interferometry, including some 20+ years for various NASA geodesy programs. We can now measure baselines and station locations all over the world with precisions of better than a cm, and approaching one or two mm. If there were no atmosphere, we would be sub-mm instantly on any length baseline.

Shawn - thanks for pointing out the Swift unit. Also, in regards to your original angular measurement idea, did you consider how accurately you need to measure the angles? For high precision, you may need sub-arcminute angular encoders.

And finally - is this a gedanken experiment or do you really need/want one of these?! (As I have learned over the years, "want" and "need" may or may not be the same!)

At any rate, the various schemes that could be applied are interesting to see.