OpenStreetMap
I am a novice. The Garmen tracker is new, just a few days old.
The tracks are erratic. The altitude show large altitude differences although I am in flatland (+/- 10 meters.
When tracking I am sometimes up over 500 meters from the Garmen map.
For example. On Tuesday I was cycling northwards on the west bank of the Rhine river. Garmen map showed me to be on the East bank of the river heading north.
I admit I may be doing something wrong, but I can't figure out what that could be.
I have sent an email to Garmen but have received no reply
Please advise
dcp in Rheinbach, Germany
Discussion
Comment from ColinMarquardt on 19 June 2008 at 07:58
Make sure you have EGNOS enabled in the settings. High variance in altitude on the other hand is to be expected (although +-10m is quite good).
Comment from HannesHH on 19 June 2008 at 08:20
Make sure to leave the unit get its position before you start traveling. Otherwise results are often wacky. The garmin map (if you mean the one that comes with Map Source) is highly inaccurate. According to it I live in the water. ;)
Comment from daveemtb on 19 June 2008 at 08:26
To get the best possible accuracy from a GPS unit, give the unit some time to acquire satellites and download the ephemeris data. To download the satellite data you need a good signal, stronger than that needed to maintain a lock. Try placing the GPS somewhere stationary with a good view of the sky for 15 minutes or so before you next use it. I find that placing my GPS on a south facing window for a while, then a north facing window for a while helps if I don't want to go outdoors.
If the unit is new it is possible that it hasn't had a chance to download data from the satellites yet, and is only using a few to obtain a lock. Do you know how many satellites it is locked onto most of the time?
Also, note that for best reception you want a clear line of sight to the sky as possible. Are you using the GPS in a pocket? I always find this causes bad performance. If you are in a wooded area or amongst tall buildings you will find the tracks are innacurate. It's just a limitation of current GPS technology.
+/- 10m on altitude is to be expected I'm afraid, unless your GPS has a barometric altimeter.
Comment from photohiker on 19 June 2008 at 09:32
I posted the other day that the patch antennae models (Vista HCX in my case) work better in marginal situations like wooded valleys when the unit faces the sky. I've modified my daypack harness to hold it in that orientation, and I've noticed a lot better accuracy since.
The 60CSx has a better antenna, try keeping it high on your person, and always with a good view...
Comment from POHB on 19 June 2008 at 14:45
If you appear to be 500m out on the Garmin map I suggest you try a different map, like erm... OSM? You could also try uploading a track and see how it looks in Potlach compared with the map.