[jinnko]

I don't get it, are the figures here typos?

> Given that GNSS satellites typically travel in medium Earth orbit, approximately 20,000 km or 12.4 miles above the surface, GNSS systems are well suited for detecting fluctuations in ionospheric density. > > Further, because ground stations can detect GNSS satellites from such a significant distance (up to 1,200 km),...

Should that be 2000 km and 1240 mi?

[lxgr]

No, GNSS constellations are indeed usually in MEO, not LEO.

Using MEO means that they'll need fewer satellites for global coverage at acceptable elevation angles than they would in LEO, and since navigation signals are very low data rate, power is usually not a limiting factor either.

[tonyarkles]

I believe around 19,500km is the correct number from some past work.