Re: [gpsd-dev] Planning a 3.11 snap release

[Eric S. Raymond]

Greg Troxel <address@hidden>:
> Also, let me know what kind of GPS receiver and antenna works for
> submarines.   I am actually curious how far under water it might work,
> but I bet it's at most a few meters.

Yes, I'm told you can get GPS signals several meters down.  The way these
nav sytems are designed is to nearly surface to get position fixes, then 
dead-reckon using thrust calculations and accelerometers in deeper water.

Additionally, I'd bet money that the military uses lidar on seabed
features to tell how actual velocity differs from dead-reckoned. It's
what I'd do.
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>

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