Steve Bennett wrote: > I've got a trace from today which is significantly out of sync with a > path I traced from Nearmap: > > http://www.openstreetmap.org/edit?lat=-37.880138&lon=145.193417&zoom=19&gpx=594988 > > <http://www.openstreetmap.org/edit?lat=-37.880138&lon=145.193417&zoom=19&gpx=594988> > > The trace looks like I was wandering through the grassy paddock, but I > was actually following exactly that northern most "highway=path" in > the bush. So it looks like the trace is incorrectly recorded something > like 50m north of where I actually was. Now, since the discrepancy > seems to go away on that track a bit further east (later > chronologically), presumably the explanation is the GPS data is > faulty. Is this common? I'm new to GPSing, so I'm just surprised. It's > a Garmin Oregon 550. Is there anything I can do to reduce, or at least > detect, such errors? > > Steve There are some good points in the previous messages, but I think there's an overall strategy & that's:
Don't be a slave to your GPS. Be aware of your surroundings - Are you in thick undergrowth? Are you traveling at the bottom of a steep cliff? As has been said, keep an eye on the accuracy reading (except if you're driving of course!) If you are in an area where reception is poor make a note of it, either with a waypoint or, as I do, with old fashion paper & pencil. I take photographs to help me remember what my route looked like. I find it extremely useful for recalling road signs & street names. If your trace goes straight across a field, but you know you walked around the edge of it, mark it as you walked it, taking a best guess as to where you went. Then tag it with a note or Fixme explaining that it needs updating. Cheers Dave F. _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk