Weirdest Thing On Gps

[inventorjg]

Today while out caching with my Dad, I wanted to get a reading of how far we had to go. It said something like 1 mile, when it had just said .19 miles. Then I looked at the "mph" reading, and it said 28.1 mph and I was standing still! That was weird! It was probably something messes up with the sats.

 

Post your weirdest experiences with a GPS...

[ucmike]

my magellan freaked out during last winter and showed me miles from a nearby cache and had me at an elevation of 10,000+ feet...not likely here in central NJ. it insisted on that for several minutes until i gave up on the cache. it came back after being turned off for a while. never did it again

[+leatherman]

I've experienced something similar.

I blamed my experience on unplugging my Meridian from car power without turning it off.

I was standing on a wooden bridge over a ravine. The satellite signals started bouncing up and down. I lost all the locks and only one or two would flash up and down on the satellite screen.

I sat down to wait for it to settle down. I sat there for twenty minutes. When I received enough signals to get a position, I was in Vietnam! I saw that I was moving. I found myself flying across the Pacific at 300mph. Weird! it took me an hour before I could use the thing. I finally made it to the cache though.

 

I had a similar experience with my Map330 a couple of years ago. I blamed that one for using it in a car with window tinting.

 

I'm just guessing though.

[+SBPhishy]

I blamed my experience on unplugging my Meridian from car power without turning it off.

 

I've done that at least a hundred times. No problems...

[+Butano]

I won't say what I was doing when I record this max speed. Mostly because I must have blacked out and don't remember Take a look at the Max Speed towards the lower right corner.

[+Naefearjustbeer]

I have had my etrex showing that I was driving at 264mph when I was actually doing about 60mph

[The Big Kid]

Believe it or not, I think I have a logical explanation.

 

When calculating your position the reciever calculates the distance from the satellite, if it starts with only 2 satellites and has moved since the last time you moved it, it recalculates from square one. Most recievers have a small memory that will remember where it was when it was turned off, and begin aquiring assuming that it is near that position. If it finds that the satellites are relatively close to what they thought, it figures it out fairly quickly. If not, it could take awhile as it might only have 2 distances from a satellite to work with, and usually, the 2 distance circles intersect in 2 different places. It then has to figure out which intersection is the right one.

 

an example: on a piece of paper, place 2 dots approx 6 inches apart, now from each dot(call it a satellite), draw a cirlce around it, 4 inches in radius( your distance from satellite), there will be 2 intersections. One of which it where you are. Imagine this over thousands of mile circles.

 

This explains the reciever being lost in Asia and taking awhile to recalculate its position.

 

high speeds while standing still, watch the estimated error number, as your position error decreases, your position may change to now be within the new error probability circle, and thus your position may move a great speeds based on how quickly the error decreases.

 

I have seen these errors many times in my career working with a GPS that is mounted on a helo that sails on the back of a ship. we turn it off, put the helo in the hangar and it could be hundreds if not thousands of miles away when it comes on next. If we don't give it a rough idea where it might be, it takes a long time to figure out that it is still in the Pacific ocean.

 

this might help, I hope. it should mean that there is nothing wrong with the equipment.

[+Imajika]

I used my Legend on a flight home today. It showed speed of 605...but it showed elevation of 4200 feet. After a few minutes, it fixed itself and showed an elevation of 36000.

 

I was pretty worried for a few minutes. At only 4200 feet in the air, we would have run smack into the Rocky Mountains.

[+Spoo]

One time, about 150 miles from home, I punched in 'Go to Home'. It showed HOME as 400 miles to the North of my location, when, in fact, HOME was 150 miles to the South. I had to shut the unit off, restart and lock and do it all over again. Everything was fine then.

This was on my first GPSr, a low end Magellan.

[+Criminal]

I wonder if this has someting to do with the way Magellen handles the loss of signal. Garmin will tell you you've lost the signal, while Magellen will attempt to extrapolate your position using the data it had before the signal loss. If the data becomes confusing it may cause the processor to hiccup as the logic program get illogical data.

 

Just my guess based on the things I've read about here in the forums.

[+Sparky-Watts]

Just the other day, I found myself traveling 1238 mph backwards out of my 40 foot driveway in my Jeep.....man, I've got great brakes!

[+leatherman]

I wonder if this has someting to do with the way Magellen handles the loss of signal. Garmin will tell you you've lost the signal, while Magellen will attempt to extrapolate your position using the data it had before the signal loss. If the data becomes confusing it may cause the processor to hiccup as the logic program get illogical data.

 

Just my guess based on the things I've read about here in the forums.

Oh! That's a cheap jab at Magellan.

 

If you were really paying attention to the other threads about this topic you would know that half of the people reporting this phenomenon owned Garmins.

 

Mostly Etrex and map76. I think there was one response with a GPS V.

[+carleenp]

I had one day where my 315 said I was between 60-80 feet away from every cache. Normally it gets around 10-15. It was fine the next time I used it. I couldn't figure out what the deal was with it that day.

[4x4van]

I wonder if this has someting to do with the way Magellen handles the loss of signal. Garmin will tell you you've lost the signal, while Magellen will attempt to extrapolate your position using the data it had before the signal loss. If the data becomes confusing it may cause the processor to hiccup as the logic program get illogical data.

 

Just my guess based on the things I've read about here in the forums.

Actually, every Magellan that I've owned (well, both of them, anyway), does indeed tell me if I've lost signal. It just doesn't occur as often as it does with the Garmins!!! (Sorry, couldn't resist! )

 

I must admit, however, once while driving home from work here in Southern California, my ST Pro suddenly showed my position to be about 100 miles off the coast of Costa Rica! About 2 minutes later, it was back to normal, although I forgot to look at the max speed. Would have been interesting, to say the least.

[+wildearth2001]

My 310 showed a speed of anywhere between 20 and 4000mph when it was in my hand on the sofa. It did that for about a month then suddenly worked again. Man do I have a fast sofa or what! Also the same unit wouldn't even try to get signal when I turned it on for about a month (a year after the first incident). To fix the problem I tried taking the batteries out. The owners manual says the memory would be cleared after having no batteries for 30 minutes. I left the bats out for a week and the memory was still intact! The problem fixed itself a few weeks later.

[+travisl]

I flew from Seattle to Baltimore a couple years ago, and had my GPS (Magellan GPS Companion for Handspring) on for most of the flight. It did a fine job telling me that the land formation out the window was the Cumberland Gap, and that we were cruising at 35,000 feet at 630 mph.

 

After landing, I got a rental car, went to the hotel, dropped my stuff, then went out to hit two caches a couple hours later.

 

The first one (Daniels), it brought me to with no problems. The next one, Stoned Cache, which was just a short walk away from Daniels, was a different story. After losing signal in the trees, when the signal came back it was very confused. I went back to the car to get a clear view of the sky, and it said I was going 50 mph. This continued for a good five minutes before I decided to give up, turn off the GPS, and head back to the hotel.

 

It worked fine for the rest of my five day trip.

[+Genoist]

My magellan tells me when it's lost a signal too, but I don't think it reports this right away. I think that it waits a few seconds before it gives up and says poor coverage. This upsets me sometimes, I'd prefer to know if I actually have a signal.

[+JMBella]

I thought this was pretty wierd. maybe it's just me...

[Swagger]

I thought this was pretty wierd. maybe it's just me...