[OSM-newbies] Trust GPS or Yahoo aerial imagery?

[Þórir Már Jónsson]

I have used the Landsat images on several occasions while editing in Iceland, and I find them to be consistently off by a about 20 metres.  And that is with gps logs from several different GPS's.
 
The JOSM WMS plug-in adds the obtion to move the images around and I'm pretty sure it's there for a good reason.
 
The Yahoo! images seem to be more accuretly positioned, but they don't allow as good a zoom level as the landsat ones (at least not in Iceland) so I never use them.
 
Just my two cents.
 
Cheers, 
Thorir Jonsson

-----newbies-bounces at openstreetmap.org wrote: -----


To: newbies at openstreetmap.org
From: Rick Collins <gnuarm.2006 at arius.com>
Sent by: newbies-bounces at openstreetmap.org
Date: 09/10/2007 13:17
Subject: Re: [OSM-newbies] Trust GPS or Yahoo aerial imagery?

At 09:01 AM 10/9/2007, you wrote:
>Richard Fairhurst wrote:
> > To answer the original question, though, trust your GPS over the
> > imagery. The imagery may not always be rectified, whereas as long as
> > your GPS has produced a good-quality track - i.e. no "concrete
> > canyon" distortions - it should always be accurate.
>
>OK. So if that's the answer (and it's sort of what I expected) then the
>follow-up question is: do we have any procedure for fixing the
>rectification, or letting Yahoo know their images are out?

Maybe you guys should take a step back and look at what you are 
saying.  You have one person with a $200-$400 GPS receiver recording 
a track which then is hand edited to add to an open source map.  This 
track disagrees with aerial imagery that companies have spent 
millions or even billions of $$$ to collect, process and 
provide.  Now you are thinking of telling a distributor of that data, 
based on your single track of collected data, that they need to 
"correct" their data.

Do you really think they are going to take you seriously?  Perhaps 
you are thinking of the Yahoo imagery as if it were a collaborative 
effort like OSM?




_______________________________________________
newbies mailing list
newbies at openstreetmap.org
http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/newbies
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/newbies/attachments/20071009/431c8c64/attachment.html>