Thousand Mile Error

[+WeightMan]

Last Saturday I started a trip south on I-5 from Seattle. I remembered just after getting into Oregon that I had not put all the maps into the 60c that I needed for I-5. I stopped at a rest stop and set up the laptop to transfer maps. I stopped the 60c from navigating to avoid potential problems with the maps and hooked it up to the laptop. After selecting the maps I needed, I dowloaded them to the GPSr. I unhooked theunit after the reboot was done. It quickly acquired sats and showed and EPE of around 20 feet. I packed up the laptop and walked back over to the car. About the time I got to the car the 60c showed loss of satellite reception. AFter I connected it to the car for power and selected the nearest cache, I set it on the dash while I got ready to leave southbound.

 

After it got reception again I took a quick look to make sure it was showing me southbound on I-5. The directions told me to go west to I-90. That was a little strange since I-90 is 200 miles north of me and runs east-west. At that point I looked at the coordinates it was showing. Instead of a longitude near 122W it showed 107W. The total distance to the cache was over 1000 miles. The EPE was still near 20 feet. Since I was driving south on I-5 it recalculated several times and still showed the same error. The only thing I could think of to do was to shut the unit off and restart. That cleared up the problem.

 

I did not check the coordinates when it first came up with coords so I don't know if the error came right after the reboot or later on.

 

Any ideas on what might have been going on? I might add that it caused no more problems the rest of the day Saturday nor Sunday or Monday while traveling south.

 

Edit to note that the location it was showing was in Montana while I was in Oregon.

Edited July 12, 2005 by WeightMan

[robertlipe]

On the edges of lost lock, the unit will sometimes get confused. In poor receptions states, my 60CS has sometimes teleported me to states that aren't adjoining. I even had a quick trip to Cuba once. (The tracklog on that was interesting. :-) When I found I was 600 miles away from the cache, that I was 200 feet from only moments earlier, I was suprised.

 

The solution is to give the unit a better view of the sky. If it gets really hosed, you can give it a hint with the 'select new location' which forces it to discard current location information and not even fake a location until it has a lock again.

 

As an aside, EPE is a much more useful metric for lost lock on the Magellans I've used than it is on my 60. When a Magellan loses lock, the EPE will soar to hundreds of feet giving you a nice warning that it's about to give up. The Garmins will happily report a low EPE while lying about your position/direction.

[+WeightMan]

I have noticed that from time to time the Garmin will continue as if I were going straight while I know I turned back there aways. If I check the sat page, that happens when I am only reading one or two sats. It will never give a new position after a loss of signal with less than four birds so it had a reasonable view of the sky when it reported the 1000 mile difference. Yes, I was in some trees at the start, but most of this was while on the freeway. No trees overhead there.

[vagabond]

It happened once with my Gold, I was in a narrow canyon in east San Diego County about 40 or 50 miles from the coast, and it showed me by Oceanside about 80 miles away and traveling at over 200 miles per hour, when I got back out into an open area it cleared up and had no more problems.

[+Marcie/Eric]

It happened once with my Gold, I was in a narrow canyon in east San Diego County about 40 or 50 miles from the coast, and it showed me by Oceanside about 80 miles away and traveling at over 200 miles per hour, when I got back out into an open area it cleared up and had no more problems.

This happened to me on my Merigold. I had a crummy lock or something, and it calculated me just west of Lake Tahoe - about 80 miles, ATCF.

[+Jolly-Rodger]

Last week, my buddy (who is GPSr challenged) was driving while we were on a road trip. I had my 60c on the dash when I fell asleep for a few hours. When I woke up, it said we took a slight detour, a few thousand miles off coarse. It also said the max speed was 700 mph. I didn't think I slept that long.

 

-JR