[time-nuts] How well does GPS work in the Arcitic?
jimlux at earthlink.net
Mon Aug 14 21:04:21 EDT 2017
On 8/14/17 5:12 PM, Bob kb8tq wrote:
> At the time all this was figured out, the idea of the military needing nav at the poles
> was pretty far fetched. They accepted a bit of degradation in those regions as a result
> of this thinking.
I don't know about that - I think it was more that it was "good enough"
everywhere, all the time.
And polar nav, pre-GPS, was really tough - Omega had the same ionosphere
problems that GPS has, etc.
I recall reading somewhere that one of the justifications for GPS was
more accurate midcourse guidance for ICBMs and those trajectories tend
to be polar. OTOH, in that application you also have IMU and
(potentially) star tracker data.
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