Newbie questions regarding accuracy of GPS...

[joerf3]

I purchased a Garmin c330 a few months ago and have had no problems with it using it locally.

 

I have a couple of questions...

 

1) This past weekend, I planned a road trip from Phoenix to Los Angeles with the unit. About an hour into the trip just outside of Phoenix, I started getting messages on the unit that it lost satellite reception. Again, this is Phoenix where there the sky is always clear (not a cloud or any other obstruction in sight). This occured on and off heading west on I-10 (open desert) for about the next 30 miles. Any ideas what would cause this reception problem on a perfectly clear day?

 

2) Next, on the way home, it gave me a different route once I was back in Arizona. Knowing the right route, I ignored the unit and continued on my way. When it recalculated the new route (the way I was planning to go), it knocked 15 minutes off of my arrival time as compared to the route the unit originally calculated. I have the unit set up for Fastest Route. Why would it give me a route that would take 15 minutes longer?

 

TIA

 

Joe

[+Red90]

1) Aliens.... Who knows really, it shouldn't do that, but strange things happen in certain locations.

 

2) It is just a little tiny computer. It can't reasonably check every possible route to find the fastest. It does what it can with the programming it has.... Fortunately, your brain is a lot more powerful. Normally, I think this is because of small errors in the maps. It thinks you can not go a certain way because of this error and tries to get you to go another way. Once past the error, all is well again.

[CenTexDodger]

I purchased a Garmin c330 a few months ago and have had no problems with it using it locally.

 

I have a couple of questions...

 

1) This past weekend, I planned a road trip from Phoenix to Los Angeles with the unit. About an hour into the trip just outside of Phoenix, I started getting messages on the unit that it lost satellite reception. Again, this is Phoenix where there the sky is always clear (not a cloud or any other obstruction in sight). This occured on and off heading west on I-10 (open desert) for about the next 30 miles. Any ideas what would cause this reception problem on a perfectly clear day?

 

2) Next, on the way home, it gave me a different route once I was back in Arizona. Knowing the right route, I ignored the unit and continued on my way. When it recalculated the new route (the way I was planning to go), it knocked 15 minutes off of my arrival time as compared to the route the unit originally calculated. I have the unit set up for Fastest Route. Why would it give me a route that would take 15 minutes longer?

 

TIA

 

Joe

 

1. Like Red said: who knows?

 

2. i have noticed this on my old 60CS as well. It seems to me like it give undue weight and preference to interstate highways. Mine once sent me on a route that would have take an hour longer than the way I would normally have gone, just to keep me on the interstate. And wehn I had it recalc using "Shorter Distance" the route was about an hour less time. They are not perfect, but they will get you there (evetually )

[joerf3]

Thanks for all the info.

 

Having the GPS unit certainly beats printing out Mapquest pages (that are usually wrong).

[+redcoyote12]

Yeah, stupid aliens. Or the Air Force base at Luke was jamming you? I bet they get bored flying around out there and pick on us civies.

 

Welcome to the forum btw... where in Phoenix are ya?

[+HitchHiker76]

I purchased a Garmin c330 a few months ago and have had no problems with it using it locally.

 

I have a couple of questions...

 

1) This past weekend, I planned a road trip from Phoenix to Los Angeles with the unit. About an hour into the trip just outside of Phoenix, I started getting messages on the unit that it lost satellite reception. Again, this is Phoenix where there the sky is always clear (not a cloud or any other obstruction in sight). This occured on and off heading west on I-10 (open desert) for about the next 30 miles. Any ideas what would cause this reception problem on a perfectly clear day?

 

2) Next, on the way home, it gave me a different route once I was back in Arizona. Knowing the right route, I ignored the unit and continued on my way. When it recalculated the new route (the way I was planning to go), it knocked 15 minutes off of my arrival time as compared to the route the unit originally calculated. I have the unit set up for Fastest Route. Why would it give me a route that would take 15 minutes longer?

 

TIA

 

Joe

 

I too was on the road from from LA to Phoenix this last weekend and had the same thing happen to me. I thought that it was really weird. As this was the first trip that I made with this GPS unit I thought that it was the unit had considered returning it. But as that was the only time that it did it on the whole trip I determined that it was a fluke. Well just to thought that I would drop in and add my 2 cents worth.

[+miles58]

I purchased a Garmin c330 a few months ago and have had no problems with it using it locally.

 

I have a couple of questions...

 

1) This past weekend, I planned a road trip from Phoenix to Los Angeles with the unit. About an hour into the trip just outside of Phoenix, I started getting messages on the unit that it lost satellite reception. Again, this is Phoenix where there the sky is always clear (not a cloud or any other obstruction in sight). This occured on and off heading west on I-10 (open desert) for about the next 30 miles. Any ideas what would cause this reception problem on a perfectly clear day?

 

2) Next, on the way home, it gave me a different route once I was back in Arizona. Knowing the right route, I ignored the unit and continued on my way. When it recalculated the new route (the way I was planning to go), it knocked 15 minutes off of my arrival time as compared to the route the unit originally calculated. I have the unit set up for Fastest Route. Why would it give me a route that would take 15 minutes longer?

 

TIA

 

Joe

 

It always does that near Area 51

[+scotte]

It's not unusual to lose reception if the unit is sitting on your dash and the satellite geometry isn't favorable, that happens frequently with my GPSMAP76 in my pickup (vertical windshield, lots of steel), but never if I plug in an external antenna. I don't recall it ever happening in our Subaru, which has a much more swept-back windshield.

 

Switching to the overview screen that shows signal strength and relative satellite position may give some clues. I.e. if you are heading north but most of the SVs (satellites) are overhead, towards the south, or otherwise blocked by the cab of your vehicle.