Re: [gpsd-dev] ✘magnetic variation

[Gerry Creager - NOAA Affiliate]

On Sun, Jul 28, 2019 at 18:03 Hal Murray <address@hidden> wrote:

address@hidden said:
> Not sure how much of an issue in practice.  IIRC GPS is flaky in the high
> arctic because the orbital inclination of the sats means you seldom
> get one above the horizon.

GPS satellites are high enough that you can see them over the pole.

http://users.megapathdsl.net/~hmurray/time-nuts/Arctic/Polar-all.png
http://users.megapathdsl.net/~hmurray/time-nuts/Arctic/Polar-A.png

Yes, but. The Red Books do have specific performance limits near the poles because of geometry limitation. The constellations  are still maintaining a 55 degree inclination. While horizontal positions might be readily determined, vertical would remain difficult.

Gerry

--

Gerry Creager

NSSL/CIMMS

405.325.6371

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