There's no loss of signal though during the warm-up laps where it also happened, the accuracy on the garmin was reported as being good seeing lots of satelites weel, and this is a completely open course, no trees, no nothing, it's mounted on the bike with a clear view of the sky. And the logs going to and from the event, and every other log - including a cycle race in a different location were fine.
I also think that the signal returned at the same points in every lap, and lost at the same points in every lap make that unlikely. Cheers, Jim. 2009/4/30 Eric Fischer <[email protected]>: > When my Garmin (eTrex Legend HCx) loses signal, it continues logging as if I > had continued in a straight line for 30 seconds before either regaining > signal or giving up and stopping logging, and I imagine you are seeing > something similar. > > I see this all the time when going into tunnels and worked around it by > postprocessing the logs to drop any run of entries with identical or > near-identical latitude and longitude deltas (to within 0.000002 degrees) > leading up either to the end of a log or to a sudden change in speed > (increasing or decreasing by 10mph in a single second). > > Eric > > > On Wed, Apr 29, 2009 at 4:39 PM, Jim Ley <[email protected]> wrote: >> >> Hi, >> >> Last week, and tuesday I did a cycle circuit race, previously (couple >> of months ago the tracklog has been >> pretty flawless, but both the last two times it was interestingly and >> consistently >> wrong on every lap, the same errors also happened on my girlfriends >> Garmin. The logs were both recorded on a Garmin 705, you can get a >> gzipped version of the tcx file here >> http://jibbering.com/2009/04/screwy.tcx.gz (or screwy.gpx.gz for a gpx >> version of it) >> I also uploaded it to http://connect.garmin.com/activity/3973718 From >> which you can see that the >> Garmin recorded the distance log right (as the speed graphs are pretty >> much correct) but the GPS positions were all way off. >> >> What happened was essentially that in a number of areas on every lap, >> the log went crazy, and instead of following where I went, it went in >> a weird straight line off course. In the map view of it >> http://jibbering.com/2009/04/screwy.jpg or on the >> satellite view on the garmin page you can see the circuit clearly, and >> previously the logs have been accurately following it, but in both the >> last two weeks races >> it was just in a couple of parts of the course where it was on course, >> the other times being peculiarly off course, with weird straight lines >> - not just the ones where it suddenly jumped. >> >> Anyone have any insight into why this might've happened? Particularly >> to two seperate devices. >> >> Also if anyone can think of a relatively simple way to "fix" the log - >> to a reasonable approximation I would be happy. >> >> Cheers, _______________________________________________ Geowanking mailing list [email protected] http://geowanking.org/mailman/listinfo/geowanking_geowanking.org
