position accuracy question

25.07.2010 17:59, TheDuck wrote:


and it knows the geometry of sat positions relative to each other
affecting precision. And it knows the precision of the map shown. All
this defines the size of the displayed ring. This is a fact.


--

Heinrich
http://www.gartrip.de

wrote:


Why would, for example, the scant detail base-map have an intersection
between two major highways defined with less positional accuracy than a map
set that has lots of details. It doesn't make sense. Lack of items doesn't
mean less precision, it only means less points are plotted, not the
accuracy of all their respective locations of those points on those maps.
And why would that be reflected at all in the GPS's determined margin of
error? It doesn't make any sense whatsoever. So until you can cite some
technical literature explaining this it is NOT any kind of fact.

If I zoom into an intersection in City Navigator, presumably the one with
the most roadway accuracy lately, then turn that off and only use only the
scantily plotted base-map, the intersections on each map are within 10 feet
of each other.

wrote:

map
doesn't
maps.

It is a fact which was explained in this ng a long time ago. I think
that it even appeared in one of the manuals.
=20
Believe it.
=20
--=20
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in =
Argyll, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather

On Mon, 26 Jul 2010 08:26:21 +0100, Alan


It was explained in a newsgroup that the earth is flat too and that there
were no lunar landings.

Believe it.

Care to cite some better authority than a bunch of wannabe-experts who only
pretend to think they know what they are talking about?

Until you do it is NOT a fact, its just more newsgroup troll's bullshit
being passed along by one uneducated newsgroup troll to the next. The whole
internet is flooded wall to wall with such "facts".

wrote:

only

See:-
http://www.garmin.com/garmin/cms/site/us/support/searchsupport?search_key=
=3Daccuracy+circle

Question: What is the circle around my position on the map?
Answer:
This is the "Accuracy Circle". This circle represents the approximate
accuracy of the GPS position based on the Estimated Position Error (EPE)
and the map data quality. The position of the GPS device on the map
should be located somewhere within this circle. This feature can be
turned on or off on the GPS device. Please refer to the owner's manual
for instructions in doing this.

Believe it.
=20
--=20
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in =
Argyll, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather