GPS is wacky

If your Garmin is in error they want to know. I have done this twice now and they fixed the error on the next update. They also responded thanking me for the info. Both of my Garmin's a 1490LMT and my RV 760LMT work awesome. Do not blindly follow the suggested routes if they are shortcuts, it might not be where you want to be. you should have the big picture in your head to start with. I did the original map update and further updates at least twice a year....Try to out wit your GPS, it's hard but can be done......Mike

Last year while returning home due to an A-Fib attack, our old 850 NUVI got us thru Canada North of Calgary as Calgary was closed because of flooding. Unit is six years old and never updated and still came up with many gravel back roads to guide us. Even the Mounties when asked couldn't tell us exactly where to go.

The answer to your problem is very simple and I have had to deal with it for years.

Cartographers (map makers) have to work from survey data reported to them be field teams. There is a very simple problem there. Until the advent of price electronic navigation, finding your actual location on the globe took a lot of hard work. The U.S.A. has always been careful about this, but there are still lots of fun stories. (Look up Isle Royale.)

It happens that the Canadian surveys were never all that good and great care had to be used when counting on their published marine charts. They are getting better. So, when traveling by land in Canada, the GPS location and the published map may disagree, but the lat/long provided by the GPS is probably correct. The map data supplier to the program builder was probably in error. The error may be consistent, or it may not.....

Along the Alaskan coast, my GPS agreed with the USCGS charts, but once inland there were problems. With the population of Alaska, there was no real interest in creating high accuracy maps for drivers. Much of the area of Alaska has bee re-mapped with overflight and satellite data and I am told that it is now pretty good.

Matt

DiskDoctr wrote:
You likely are not getting a good signal from enough satellites. Mountains, declination, obstructions, and direction you're facing are common interferences.

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.

GPS satellites don't use geosynchronous orbit. They use medium earth orbit and they actually orbit the earth and aren't stationary.

Anyway, I can't believe the OP was told something about "Canadian satellites with different info".

You likely are not getting a good signal from enough satellites. Mountains, declination, obstructions, and direction you're facing are common interferences.

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.

It is not the GPS that is the problem, it is the quality of the information entered. Back a few years ago I found a Randy Map that on one page had everthing backward and covering about 1/4 mile of roads. So if you wanted to go to 118th street you had to go tot he left off the main street not the right, the right side had the streets that were on the left it was just backwards. Anyway it is best to use your GPS and a real map to varify the route.

Bob Vaughn wrote:
...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...

:B That is hilarious, I think you've been had. There are no Canadian satellites, they are all the same.

Your map software is bad and you may experience a poor signal because the further you are from the equator the weaker the signal might be.

Many don't realize that the maps loaded on a GPS are outdated when loaded. They are usually 2 - 3 years old already due to the cost of updating to the newest maps.

Driving on the NPS Blue Ridge Parkway near here, there's a spot where my current Tomtom always shows me being well off the road to the right, which would mean I'm inside a large rock face. The road as shown on the screen would have to be hung om air about 500' up. It only lasts for a few hundred feet, but there's also a phantom road that shows as intersecting in the same general area. No such road exists, and there's no place for one to have been.

I've noticed it several times late at night when I'm coming home from stargazing at Craggy Gardens. Hadn't really thought about it until I read this thread. I'm a bit overdue for a doing a map update now, so it may be fixed in their data base.

Jim, "Mo' coffee!"

BSN is correct, they are the same satellites since the entire constellation orbits the planet. If there is an error to be had its likely in the maps or the coordinate conversion to them.

The quick way to check the GPS is to go into coordinates mode and compare them up against a map looking for accuracy. I'm gonna guess its dead on

Don't go near the water...in Michigan or turn into any rivers or creeks. :)