Re: superhero space navigation

On Apr 7, 8:54=A0am, Leonard Erickson <sha...@[EMAIL PROTECTED]
> wrote:
> On Mon, 07 Apr 2008 04:41:05 -0500, Tim Little
>
> <t...@[EMAIL PROTECTED]
> wrote:
> >On 2008-04-07, Leonard Erickson <sha...@[EMAIL PROTECTED]
> wrote:
> >> Well, if nothing else, I'd like an idea as to what a normal handheld
> >> GPS unit would *do* on a trip to low orbit.
>
> >I suspect it would depend a lot on how much "sanity checking" the GPS
> >was designed with. =A0I wouldn't be surprised if most of them just
> >indicated an inability to determine position if they calculated an
> >altitude of a few hundred kilometres or more.
>
> Well, from what I read somewhere, most cheap units are deliberately
> designed to fail if they discovered they are moving above 200 mph or
> so. =A0
>
> Supposedly it's to prevent them being used as a cheap missile guidance
> system.

Not all of them are so limited. I have an old Garmin GPS III+ which
will
operate quite happily in a commercial jet - as long as it can 'see' 4
satellites out of the window. Its a lot of fun to know what the towns
and
lakes you see down there are. The ground speeds are more like 400-600
mph.

[Yes, I know, I broke the airline's current rules. Deal with it. I
didn't
use it during takeoff or landing.]

pt