[zikduruqe]

The last time I built my own GPS network, I used a sextant, a watch set to UTC and nautical tables to determine where the orbiting bodies were.

[srean]

Harrison time pieces were indeed the cutting edge GPS technology of its day. That and moon watching.

Nowadays we have GPS and Pulsar / Quasar watching.

https://en.wikipedia.org/wiki/Very-long-baseline_interferome...