[aprssig] Ambiguity due to GPS

Curt, WE7U archer at eskimo.com
Thu Jan 5 16:26:44 EST 2006

On Thu, 5 Jan 2006, KC2MMi wrote:

> Of course, that's also a mapping problem that even today most map software
> companies refuse to address. They continue to show "pinpoint" resolution, when
> they should be using position circles that are much larger blobs. AFAIK all of
> the APRS software authors, and commercial mapping authors make this same
> deception, on purpose. Including MS and Google, and the latter should certainly
> know better than to intentionally mislead users. Even DeLorme (who I have mixed
> feelings about) gave users the option to use three different sized circles for
> their GPS position, so that SOME indication of position error is possible.

A very good point.  What would be even nicer would be to use the
HDOP number to decide how much ambiguity to give the station on the
map.  That would work fine for your local station on your own map,
but we don't send HDOP in any of the APRS sentences except for NMEA,
and those sentences are way too long.

A good thing to think about though.

Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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