[Talk-ca] Fredericton WMS Offset

Connors, Bernie (SNB) Bernie.Connors at snb.ca
Mon Jan 7 19:28:31 GMT 2013

If you want to check the accuracy of your GPX files in New Brunswick you can drag and drop them on this map I created at ArcGIS.com:


As you zoom in the property lines and civic addresses will be added to the air photo map.  All of this data is published the government of New Brunswick (aka me and my co-workers).  The accuracy of this data should exceed the accuracy of the consumer grade GPS receiver.  You can read more about adding GPX files to this map in the ArcGIS.com help pages:


In the Fredericton we are displaying the 2008 air photos captured by the City of Fredericton.  They are not as current as the Bing Imagery in Potlatch but the alignment is excellent.  The City of Fredericton acquired new imagery in 2012 and we will be updating this map as soon as we have the time and resources (some time in 2013).

Bernie Connors, P.Eng
Land Information Infrastructure Unit, SNB
bernie.connors at snb.ca

-----Original Message-----
From: Andrew Buck [mailto:andrew.r.buck at gmail.com] 
Sent: Wednesday, 2013-01-02 15:59
To: nicholas ingalls
Cc: talk-ca at openstreetmap.org
Subject: Re: [Talk-ca] Fredericton WMS Offset


I am not from the area, but I did want to post my 2 cents about this issue.  Your idea of how the offset got started sounds correct.  I would caution you though that GPS traces can be offset, too, due to atmospheric effects.  To really get a good trace with no offset you need to do a few traces on different days of the same road (or path is better since it is narrow) and through an area with few buildings around as these can cause offsets, too.

Other than those issues, if you trust your traces then I see no reason not to fix the offset, but as I said make sure your traces are good first.


Talk-ca mailing list
Talk-ca at openstreetmap.org

More information about the Talk-ca mailing list