[Talk-ca] Ground Truthing protocol? --- Re: Accuracy of CanVec vs Yahoo?

[simon at mungewell.org]

> I will be interested to see what all people have to say about this. :)
>
> I for one wish I could get access to some survey-grade GPS equipment.  But
> its just so darn expensive.

Even with expensive equipment the 'tracks' can still be somewhat dubious.
The biggest problem OSM has is that there's no measure of quality stored
within the tracks (although it is technically possible to include
PDOP/HDOP/etc values with the GPX).

Ultimately you have no idea whether I was using a $25,000 L1/L2/RTK system
or a $150 garmin slung in a back pack, this means that I'm the only one
who can really say whether my tracks are 'golden'.

Multiple tracks through the same area might hint at a quality measure, but
also may be subject to the same interference such as multipath and
obstructions.

Simon.