GPS navigation

Hi all,

I am writing my conclusion and summary to this so-called 'debate' I'm
having (the one which prompted me to come here and alt.satellite.gps to
seek expert advice and opinion).

Would it be considered discourteous or bad etiquette if I were to quote
some of the opinions expressed in this thread into my summary?

Or shall I just refer my opponent (and effectively our readers as it's
an open debate) to this usenet group?


Regards,

David.

"David W" wrote

Would it be considered discourteous or bad etiquette if I were to quote
some of the opinions expressed in this thread into my summary?

Or shall I just refer my opponent (and effectively our readers as it's
an open debate) to this usenet group?

Quote away, as far as I am concerned.

It is bad to quote private E-mails on Usenet, but I don't think it is bad to
quote something already in public view, into private communications.
--
Jim in NC

To the OP:

Your "friend" may be thinking of the "datum plane", which is the
almost spherical object that is the mathmatical model of the
earth.

And there are other navigational systems for aircraft. Military
aircraft (IIRC) are inertial guidance systems rather than GPS.
Or at least they used to be.

On 2006-06-11, David W wrote:
"GPS is optimised for sea level, Blanchefort [a mountaintop ruined
castle] is 467 metres above sea level, couple this with a slant range
to a satellite of several thousand miles and the curvature of the earth
and you have error. At least up to 100 metres..."

Well, in a light plane cruising between 4,000 and 8,000 feet, my
handheld Garmin 195 reports an estimated position error of 13 feet -
about 4 metres. Your friend doesn't know what he's talking about.

The map is only optimized for aviation in that it depicts airspace - the
receiver itself and the way it generates the map is no different from a
GPS for use by sailors or drivers or hikers.

--
Yes, the Reply-To email address is valid.
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de

Thomas Borchert wrote:

I can see how the basic principles are the same, but I'm guessing my eTrex
wouldn't be happy with the speeds the shuttle is doing.

Many cheaper GPS receiver do indeed have a speed limit. Is it given in the
specs for the eTrex?

There are technology export regulations that limit GPS receivers to
operation below altitudes of 60 kft or below speeds of 1000 knots.
Most consumer models, including the eTrex, are specified to work up to
those limits. However, some units have lower limits - for example,
most Magellan models specify a maximum speed of 951mph.