[Talk-ca] GPS inaccuracy

[Tom Taylor]

I will do a resurvey in the way you suggest. It was really disappointing 
to find I couldn't trust my GPS at all (well, I did some mental 
adjustment of waypoints to place building entrances), and being off by a 
constant amount for 4 km certainly makes one suspicious.

A bit to the north, my GPS survey of some footpaths behind a school 
matched Bing nicely. It would be really interesting to find some sort of 
disconnect in between.

Je manquais de la courtoisie envers les francophones qui suivent cette 
liste. En sommaire, j'ai tracé une piste de longueur totale environ 4 
km, mais l'a trouvé toujours environ 10 metres à l'ouest des entités 
déja presents sur la carte et les images Bing. Je vais faire un autre 
sondage pour mieux comprendre la situation.

Tom Taylor

On 19/11/2012 8:37 AM, Connors, Bernie (SNB) wrote:
> Tom,
>
> The transmission lines would not affect your GPS accuracy.  I agree
> with Pierre that you could repeat the track and see if the two tracks
> are similar.  Another thing you could do is identify several
> identifiable points in the Bing Imagery such as the intersection of
> two sidewalks, the corner of a sports field, etc.  Go to those points
> and use your GPS to record a waypoint and use position averaging with
> about 3 minutes of recording to get a more accurate location and then
> compare those waypoints to the Bing imagery.  Position the Bing
> imagery so they match up with your waypoints and then look at your
> GPS tracks top see how they line up with the Bing Imagery.
>
> Bernie. -- Bernie Connors, P.Eng Land Information Infrastructure
> Unit, SNB bernie.connors at snb.ca
>
...