+muns02 Posted October 4, 2008 Share Posted October 4, 2008 (edited) So I spent day 1 with my OR today (after updating to v2.5) and found that while driving around town I'm consistently 80 to 120 ft offset from the road drawn on the TOPO basemap. Is there some setting I'm missing? I tried to setting the GPS to WAAS mode to see if there was any difference - there wasn't - but am unsure if it ever acquired (how do I know if its WAAS?). This concerns me as I am now questioning the overall accuracy of this unit. Anyone else have a similar experience or suggestion for me? Edited October 4, 2008 by muns02 Quote Link to comment
+storm180 Posted October 4, 2008 Share Posted October 4, 2008 Basemap is only used as a reference. You need other maps for more accuracy. Quote Link to comment
+GeekBoy.from.Illinois Posted October 4, 2008 Share Posted October 4, 2008 So I spent day 1 with my OR today (after updating to v2.5) and found that while driving around town I'm consistently 80 to 120 ft offset from the road drawn on the TOPO basemap. Is there some setting I'm missing? I tried to setting the GPS to WAAS mode to see if there was any difference - there wasn't - but am unsure if it ever acquired (how do I know if its WAAS?). This concerns me as I am now questioning the overall accuracy of this unit. Anyone else have a similar experience or suggestion for me? The Garmin Topo roads are notorious for being inaccurate. I live near the IL/WI state line, and there is one road which is right on the state line. It has an IL name/number as well as a WI name/number. When I look at the Topo 2008 maps from Garmin, I see two roads paralleling each other about 200-300 feet apart. One is IL name/number and the other is the WI name/number for the same road. Neither of the roads on the Topo map matches the track log from my GPSr. If I look at the City Navigator 2009 NT maps, there is only one road, and it matches the track line from my GPSr (with lock on roads turned off). I almost always use the City Nav maps now based on this experience... Quote Link to comment
+Okiebryan Posted October 4, 2008 Share Posted October 4, 2008 (edited) That is a scaling and/or rotation issue. Surveyors and GIS people deal with that all the time. When you paste maps together, and line it up at a few georeferenced points, there will almost always be some error like that. Just zoom out a bit, you hardly even notice it then. Edited October 4, 2008 by Okiebryan Quote Link to comment
+muns02 Posted October 5, 2008 Author Share Posted October 5, 2008 That is a scaling and/or rotation issue. Surveyors and GIS people deal with that all the time. When you paste maps together, and line it up at a few georeferenced points, there will almost always be some error like that. Just zoom out a bit, you hardly even notice it then. Thanks all for the input! Took a drive today and did find that adjusting the zoom put me back on the road. As long as it's expected error I won't worry too much. I did pocket 9 caches today, so it can't be too far off! Quote Link to comment
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