My GPS went insane today. Why?

[+d+n.s]

I have very recently gotten into Geocaching with my wife. A buddy of mine talked us into trying it with him a week or so ago (it was his first time too) using his iPhone.

Today we drove down to a different city to move a coin we found and show our other mutual friend the fun.

 

Well, things didn't go great.

There were two city parks in her area full of caches. We wrote down the coords and any essential info we thought we might need and headed out.

 

However, in both parks our GPS was acting crazy. The point we were traveling to kept moving and never got closer. our direction kept shifting and I'm pretty sure (based on the clues in the cache description) the initial coordinates weren't correct.

 

Since we are new at this, young and low on money we have been using our Garmin Nuvi 255w in pedestrian mode. So far its worked well for us with urban caches and I ouldn't necessarily try to take it out to a big state park but surely it shouldn't go insane in a city parks, right?

 

(Maybe) Helpful details:

It was cloudy (I've read it shouldn't matter)

One of the parks just did a bunch of construction and added new paved trails.

We used it later to find a cache in the city, but the sun had come up a bit :/

 

Sorry if this question is awful. Its my first one, be gentle.

 

EDIT: If it matters I was looking for this guy the longest to give you an idea of geography

Edited May 10, 2010 by d+n.shults

[+Bear and Ragged]

surely it shouldn't go insane in a city parks, right?

 

It's a car satnav, it wants to keep you on the road.

Even in pedestrian mode.

Pedestrian mode allows you to go 'the wrong way' on a one way street, rather than follow the one way system around.

 

Yes, you can use a car unit, but a proper hand held GPS will be far superior.

 

Welcome to caching, hope you don't get to disheartened by you experience so far.

[daveindeal]

when i first started i was using a tomtom it was ok when combined with google maps or g-earth an i managed to clock 11 caches that way.

 

its ok if the caches are at the roadside on or near payments but as soon as you move away from the road/path its useless.

 

one cache the tom tom said that i had arrived at destination a long search and 3 visits back, still no find, when i got my blackberry and blackstar first visit back it was found - a 12 meter distance further from the road into the undergrowth

[+Gitchee-Gummee]

First of all, even the most seasoned cacher is going to have DNFs. Even on what should be easy ones.

 

Just like the bumper sticker says, "It Happens!".

 

Sometimes unnoticed things can make any electronic device act goofy. Power lines, a nearby radio transmitting source, etc. It isn't that they actually affect your device, but they can (doesn't mean that they will)) block out or interrupt the incoming satellite signal should the circumstances be just right.

 

This is not always the same as RFI, it is more a case of signal blocking, and is usually only temporary.

 

Signal bounce, sometimes referred to as multipath propagation is fairly common occurrence in natural canyons and manmade canyons (cities). It can cause weird readings for a GPSr.

 

What caused your problems? We probably will never know, if it was an outside influence.

 

Beyond that, should you have been very close to GZ, you should learn to disregard the GPSr and rely on your eyes and brains for the hunt. Too often, newer GPSr users expect to walk right to the cache, but the GPSr starts sending them this way and that way, then another way. That is when you should put it away and LOOK for the hiding spot, not look at the GPSr.

 

Did this help? Probably not, but these are things you should be aware of.

[+Team Cotati]

surely it shouldn't go insane in a city parks, right?

 

It's a car satnav, it wants to keep you on the road.

Even in pedestrian mode.

Pedestrian mode allows you to go 'the wrong way' on a one way street, rather than follow the one way system around.

 

Yes, you can use a car unit, but a proper hand held GPS will be far superior.

 

Welcome to caching, hope you don't get to disheartened by you experience so far.

 

This is interesting.

 

Am I understanding that with car nav units, that when you enter gps coordinates, the unit will not and cannot direct you to those coordinates unless the entered coordinates are essentially on the shoulder of a roadway?

 

Thanks.

[+Bear and Ragged]

surely it shouldn't go insane in a city parks, right?

 

It's a car satnav, it wants to keep you on the road.

Even in pedestrian mode.

Pedestrian mode allows you to go 'the wrong way' on a one way street, rather than follow the one way system around.

 

Yes, you can use a car unit, but a proper hand held GPS will be far superior.

 

Welcome to caching, hope you don't get to disheartened by you experience so far.

 

This is interesting.

 

Am I understanding that with car nav units, that when you enter gps coordinates, the unit will not and cannot direct you to those coordinates unless the entered coordinates are essentially on the shoulder of a roadway?

 

Thanks.

They are made to 'keep you on the road' and will show their position as 'on the road' or where the unit belives it is.

It's interesting to watch a satnav when you use a new road that hasn't been updated on the units map yet. It WILL show you as being on the road on its map until you get around 100 to 200 yards away from the road.

If the new road is within that distance, and runs parallel it will show you on the old road!

 

Some (most/all?) satnavs have the ability to show you where you are as co-ordinates, so if you turn off the directions and use the co-ordinates it may be possible to find a cache, but you are not given any clue as to direction, only the numbers going up/down as you move.

But you will be walking around looking like a very drunk bee! (More than a lot of cachers do with their GPS! )

[+roziecakes]

I have a nuvi 255W as well. I do find caches with it, even some out in the woods, when I don't have my handheld on me. It works great, if you can get the hang of this technique. I even leave mine in automobile mode.

 

(*Note: Some newer units you can't do this with anymore, but mine is less than a year old, and it works)

 

On the main screen (where there are the "Where to" and the "View Map" icons), hold your finger down on the signal bars (upper lefthand corner) until a screen pops up with the coordinates.

 

I look at what the coordinates are supposed to be for the cache, and I start moving towards those numbers. I watch the numbers go up and down, and follow the numbers in the right direction until I get to the coordinates listed on the cache page.

 

It actually really works. It takes a little bit of practice, but it works great when our handheld GPS is at home and I want to go caching. It took me a couple of days to get it down. I know it's not as convenient as following an arrow, but you might try it!

 

Hope that helps!

[+drfred]

QUOTE(Bear and Ragged @ May 10 2010, 04:25 AM) *

 

QUOTE

surely it shouldn't go insane in a city parks, right?

 

It's a car satnav, it wants to keep you on the road.

Even in pedestrian mode.

Pedestrian mode allows you to go 'the wrong way' on a one way street, rather than follow the one way system around.

 

Yes, you can use a car unit, but a proper hand held GPS will be far superior.

 

Welcome to caching, hope you don't get to disheartened by you experience so far.

 

This is interesting.

 

Am I understanding that with car nav units, that when you enter gps coordinates, the unit will not and cannot direct you to those coordinates unless the entered coordinates are essentially on the shoulder of a roadway?

 

Thanks.

 

The Garmin Colorado (and presumably the Oregon) have several routing modes. If you are routing to a waypoint using one of the "on-road" modes the unit will keep pointing you back to the closest road. You have to switch to "Off-Road" to navigate right to the cache.

 

This usually is not an issue as navigating to a "geocache" is different from navigating to a "waypoint" but becomes an issue for multis and puzzles.

 

From what I understand many of the car models don't have the "off-road" navigation feature.

[+roziecakes]

[

From what I understand many of the car models don't have the "off-road" navigation feature.

 

I believe that the nuvi 255W does not have this feature, at least from what I know of mine thus far. It does have a pedestrian mode, but using the method that I do for caching with it, I haven't needed to switch to that mode.

[+AuntieWeasel]

It should also be pointed out that, near ground zero, most GPS units will "go insane." It's ten feet over...no, wait, it's thirty feet behind...no, hang on, it's five feet...wait, you're standing on it.

 

And some days they act crazier than others. I've been in groups and everyone's GPS was juking and jiving all over the place.

[+roziecakes]

It should also be pointed out that, near ground zero, most GPS units will "go insane." It's ten feet over...no, wait, it's thirty feet behind...no, hang on, it's five feet...wait, you're standing on it.

 

And some days they act crazier than others. I've been in groups and everyone's GPS was juking and jiving all over the place.

 

That's very true! Also, the nuvi will tell you what the accuracy is, on a black bar on the bottom of the screen. If you can get within 15 foot accuracy, that's pretty good.

[g_o_caching]

 

On the main screen (where there are the "Where to" and the "View Map" icons), hold your finger down on the signal bars (upper lefthand corner) until a screen pops up with the coordinates.

 

Thanks for the tip nymphsatyr. I have a Nuvi 1350 and I will try that. I use "Where am I?". I go back and forth between "Coords" and "Where" to refresh reading. I usually walk the wrong way to get the numbers to match. It does work though.

When I get the numbers bouncing all over, I walk a distance away from what I think is GZ and come back to it. It usually settles the numbers down when you are moving.

Were there any UFO sightings in that area the day you were there? That could affect your readings! lol

[+roziecakes]

 

On the main screen (where there are the "Where to" and the "View Map" icons), hold your finger down on the signal bars (upper lefthand corner) until a screen pops up with the coordinates.

 

Thanks for the tip nymphsatyr. I have a Nuvi 1350 and I will try that. I use "Where am I?". I go back and forth between "Coords" and "Where" to refresh reading. I usually walk the wrong way to get the numbers to match. It does work though.

When I get the numbers bouncing all over, I walk a distance away from what I think is GZ and come back to it. It usually settles the numbers down when you are moving.

Were there any UFO sightings in that area the day you were there? That could affect your readings! lol

 

I hope it works for you! Some models of the nuvi don't do it, and I'm not sure which. It's nice because you can see the numbers moving in real time.

[+Leleboo_05]

I also use the nuvi (which i've heard is great in combo with a handheld unit) but I've had the best luck punching in the coords, driving close to where it says to go, then clicking tools and where am i. Compare with the coords written down and It usually gets me right on. Good luck!

[+d+n.s]

Thanks for all the tips.

I was indeed under power lines, but I am assuming it wasthe GPS' shortcoming though instead of user error or interference.

I only had problems in the parks and I was nowhere near where the cache was actually supossed to be in several instances. (ex: its by the soccer feild, but the GPS wants me to walk far away from said feild)

 

We will definitely try to practice nymphnsatyr's technique until we get a proper off road GPS.

 

That said, I have one more question if you folks wouldn't mind.

Under Navigation>route preferneces I have a choice for "off road"

anyone know what this is actually for?

The website support says it draws a straight line between you and the destination, but that seems pretty worthless if it freaks out as soon as you leave the road.

[+Gitchee-Gummee]

Under Navigation>route preferneces I have a choice for "off road"

This is you should switch the GPSr to after you have parked the vehicle. This is the preference that should take you to GZ w/o it trying to keep you "on-road".

[+Gitchee-Gummee]

Hiccup!

Edited May 10, 2010 by Gitchee-Gummee

[+d+n.s]

Just wanted to say that my wife and I have been using nymphnsatyr's tip with great success! Thanks.

Add a compass to the mix and it should get even smoother.

It works at least well enough to get us in the area.

Edited May 12, 2010 by d+n.shults

[+roziecakes]

Just wanted to say that my wife and I have been using nymphnsatyr's tip with great success! Thanks.

Add a compass to the mix and it should get even smoother.

It works at least well enough to get us in the area.

 

Hooray! I'm so glad to know that. Feel free to PM me if you have any other nuvi questions you need help with.

[+humboldt flier]

Your GPS'r went crazy and had you doing the drunken sailor dance because of something designed into each and every GPS'r.

 

The units detect how desperately you are seeking the cache which flips the units into SPAZ MODE. The easiest way to avoid flipping the switch is to be very, very, very, very ( yes - 4 verys ) nonchalant when in and around GZ.

 

Tee, Hee, Hee, Hee

[+Team Cotati]

In summary, if you are going to participate in the game of geocaching, do not use a unit that has been designed to perform highway and street turn by turn navigation.

 

Tee hee.....hee...hee.

Edited May 14, 2010 by Team Cotati