<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:10pt">Tom<br><br>Here is an initialization procedure to assure you will diminush the inaccuracy of measurement by your GPS. Before starting to record, you open your GPS, place it on a spot without moving it for at least five minutes. This will give time to the GPS to communicate with various satellites and better estimate your position. After this, the Satellite page should report a precision around three meters. But as Daniel said before, this is theoric and not what you will obtain.<br><div><span><br></span></div><div> </div><div><span style="font-style:italic;color:rgb(0, 0, 191);font-weight:bold;">Pierre <br></span><br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; margin-top: 5px; padding-left: 5px;"> <div style="font-family: arial, helvetica, sans-serif; font-size: 10pt;"> <div
style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">De :</span></b> Tom Taylor <tom.taylor.stds@gmail.com><br> <b><span style="font-weight: bold;">À :</span></b> "Connors, Bernie (SNB)" <Bernie.Connors@snb.ca>; "talk-ca@openstreetmap.org" <talk-ca@openstreetmap.org> <br> <b><span style="font-weight: bold;">Envoyé le :</span></b> Lundi 19 novembre 2012 10h29<br> <b><span style="font-weight: bold;">Objet :</span></b> Re: [Talk-ca] GPS inaccuracy<br> </font> </div> <br>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.<br><br>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.<br><br>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.<br><br>Tom Taylor<br><br>On 19/11/2012 8:37 AM, Connors, Bernie (SNB) wrote:<br>> Tom,<br>> <br>> The transmission lines would not affect your GPS accuracy. I agree<br>> with Pierre that you could repeat the track and see if the two tracks<br>> are similar. Another thing you could do is identify several<br>> identifiable points in the Bing Imagery such as the intersection of<br>> two sidewalks, the corner of a sports field, etc. Go to those points<br>> and use your GPS to record a
waypoint and use position averaging with<br>> about 3 minutes of recording to get a more accurate location and then<br>> compare those waypoints to the Bing imagery. Position the Bing<br>> imagery so they match up with your waypoints and then look at your<br>> GPS tracks top see how they line up with the Bing Imagery.<br>> <br>> Bernie. -- Bernie Connors, P.Eng Land Information Infrastructure<br>> Unit, SNB <a ymailto="mailto:bernie.connors@snb.ca" href="mailto:bernie.connors@snb.ca">bernie.connors@snb.ca</a><br>> <br>...<br><br>_______________________________________________<br>Talk-ca mailing list<br><a ymailto="mailto:Talk-ca@openstreetmap.org" href="mailto:Talk-ca@openstreetmap.org">Talk-ca@openstreetmap.org</a><br><a href="http://lists.openstreetmap.org/listinfo/talk-ca" target="_blank">http://lists.openstreetmap.org/listinfo/talk-ca</a><br><br><br> </div> </div> </blockquote></div> </div></body></html>