[time-nuts] GPS from a window seat
robert8rpi at yahoo.co.uk
Thu Oct 1 20:43:49 UTC 2009
Apart from the CoCom / Itar restrictions, some early portables had limits to differentiate the much more expensive aviation versions. This seems to have stopped. The Garmin GPS-II had a speed limit of about 100mph, the GPS-II+ and GPS-III didn't.
--- On Thu, 1/10/09, bg at lysator.liu.se <bg at lysator.liu.se> wrote:
From: bg at lysator.liu.se <bg at lysator.liu.se>
Subject: Re: [time-nuts] GPS from a window seat
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Thursday, 1 October, 2009, 8:27 PM
> Check the specs on your GPS... many consumer GPS units will not work at
> airplane velocities/altitudes. GPS manufacturers don't want you using a
> non aviation certified unit for airplane navigation (plus they get big
> bucks for the aviation units).
The limitations implemented is either 60kft or (sometimes both) 1k knots.
Both of these are out of reach for (current) commercial airliners. What
GPS receivers did you test that used stricter limitations?
PS a random link to the CoCom limitations
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