I have been getting some weird directions from my Garmin Gps since we have been in Canada and Alaska. Today it took me to the back woods and when I got turned around and found my way to a campground not the one I programmed into the GPS the manager told me that US GPS's have a glitch in that the Satalites that service Canada do not give the right information to US units. I think she may have a point because many times my gps will tell me to turn after I have passed the turn point...plus It seems to be a couple of miles as the crow flies off on some days....

Could you tell us the general location where the GPS acted abnormally?

We are having the same problem. The GPS goes insane in both Canada and Alaska. We took a picture of our GPS screen when we were near Fairbanks and it actually said "Go Thata Way." Good reason not to depend solely on the GPS.

I bought my most recent Garmin in the US, and brought it home to Canada. Never any problem.What model is your Garmin?

Complete ignorant BSIt's the -same- satellites.

There are multiple parts to the system. One part is the satellites that orbit the earth and broadcast to the GPS receivers on the ground, on the water, in the air, etc.Another part is the calculations that take place in GPS unit to determine a lat/long/elevation for the unit.A third is the datum used by the GPS system (WGS84) which provides a mathematical model of the earth's surface.Also, there are the maps which are used to display the location of the GPS unit, nearby roads, rivers, waterfalls, Walmarts, etc. etc. to the user.Local maps in "backwoods" areas tend to be less precise, and are often older and were produced on older and local datums which don't match WGS84 (which means that a given lat/long location (say of a bridge) as measured by the GPS could be miles away from the place the bridge shows up on the non-WGS94 map.More money and effort is spent making the maps used in the GPS in your hand or your car or RV to be accurate in busy/important areas - while out in the boondocks they may have just picked up some out of date and inaccurate map because they don't want to spend the time and money it takes to make and keep maps up to date for areas which are seldom travelled.Note that the maps used in different GPS units may have been made by different map making companies and so may not show the same position on the MAP even though they calculate the same lat/long.There are more factors (like the use of local datums in map making) that can affect the accuracy of your GPS - such as a large volcano eruption which changes the earth's center of gravity :).

GPS is wacky | Good Sam Community

37 Replies

DiskDoctr
Explorer
Jul 11, 2014
garyhaupt wrote:
I'm sticking to the idea that we have different satellites in Canada. That is a much more satisfactory answer anyway. Plus, ours are in French so as to be able to find poutine and syrup.

Gary Haupt

French? My gps has an English accent and gets snooty if I don't follow her directions ;)
crabbin_cabin
Explorer II
Jul 11, 2014
Currently in Newport OR, on a cliff overlooking the ocean (Jump-Off_ Joe) and my garmin claims I am -56 elevation!!
Mootpoint
Explorer
Jul 11, 2014
All I did was make sure I had the latest upgrades and downloads before venturing into new territory. Never had a problem to speak of.

To Matt_Colie ..... I think a big part of those problems arise from the large amount of uninhabited area going north. They probably didn't put mapping on a high priority list due to lack of population.
As normal with politicians.... Not enough people to affect the vote...why spend the money. :h
garyhaupt
Explorer
Jul 11, 2014
I'm sticking to the idea that we have different satellites in Canada. That is a much more satisfactory answer anyway. Plus, ours are in French so as to be able to find poutine and syrup.

Gary Haupt
DiskDoctr
Explorer
Jul 11, 2014
I was saying gps, but thinking data satcom :o sorry for the confusion.
SCVJeff
Explorer
Jul 11, 2014
DiskDoctr wrote:
---snip---Your gps settings should include a zipcode setting, which will adjust for declination. Also look for your satellite info display. It will show the number and signal quality of birds you're connecting to.

In Alaska the angles to geosynchronous (think "equator") satellites are awfully close to the southern horizon.
WHAT?

- So the GPS has a place you enter your Zipcode so it can locate itself? That's rather novel. I would have thought a GPS could tell you what Zip-code you were in, not the other way around.
- What Declination? We're not setting up a polar arc antenna
- Take a look at the GPS constellation. It is Asynchronous, not geosynchronous, and arguably not even that. Either way, not one of the GPS satellites in any of the three constellations out there are Geosynchronous.
haddy1
Explorer II
Jul 10, 2014
jnharley wrote:
You do have to input Lat/long coordinates up here because many places just do not have traditional addresses.

Also, you need to make sure that your lat/lon is entered in the same format as your GPS. My Garmin units have at least 3 different formats available.
pappcam
Explorer
Jul 10, 2014
You're going to run into lots of map errors out in the boonies as there isn't the desire from the mapping companies to perfectly map these places. As was stated earlier, let the manufacturer know about these things as they're always looking to improve the accuracy.
jnharley
Explorer
Jul 10, 2014
Numerous people have told us they are having the same problem with their GPS device (all different brands) in Canada and Alaska. The routing seems fine but the GPS says "make a u-turn, then an immediate left) putting you back on the correct route. Not sure why but we just ignore it and we never depend on just the GPS. We always have printed directions too. You do have to input Lat/long coordinates up here because many places just do not have traditional addresses. We have only missed one turn while on this trip and that was in Grand Prairie, Alberta because the GPS went crazy. Grand Prairie also had the worst frost heaves we have encountered and were not marked.
2oldman
Explorer II
Jul 10, 2014
pappcam wrote:
Anyway, I can't believe the OP was told something about "Canadian satellites with different info".
You hear it all on here.

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GPS is wacky

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