What am I doing wrong?

[+Sarada69]

Sometimes I will be on a search for a cache and my GPS reads 70m out yet the flag appears to be bang on where I am standing? Is this just due to overhead wires? How can I get around this to make my search easier?

[+dfx]

flag? what flag?

 

what kind of GPS device are you using?

[+Sarada69]

flag? what flag?

 

what kind of GPS device are you using?

 

A Garmin Nuvi 265w....I know, not a handheld...I'm buying that next

Edited April 20, 2010 by Sarada69

[+northernpenguin]

Sometimes I will be on a search for a cache and my GPS reads 70m out yet the flag appears to be bang on where I am standing? Is this just due to overhead wires? How can I get around this to make my search easier?

 

You're gonna need to share what kind of GPS you're using for anyone to guess what's happening. All the different devices have quirks - for example the Garmin Colorado can show significant position errors if you're running the 2.6 firmware (vs the current 3.4 firmware) but that's not going to help you if you're holding onto a Magellan eXplorist.

[+dakboy]

Power lines directly overhead will definitely mess with your GPSr.

 

Car GPSrs don't have to be as accurate as handhelds as they work on a larger scale - you don't need to know things down to a few feet when you're traveling at 30MPH. But you do have to calculate routes, position, etc. quickly because of the speed you're moving at. So there may be an accuracy vs. speed tradeoff done in the software too.

 

Also, no GPSr will be 100% perfect every time (consumer handhelds at best get down to 3-4 meter accuracy) and you don't know how accurate the cache owner's own coordinates are (I had a multi this morning where each waypoint was 20-25 feet off, consistently). Use the GPSr to get you into the right area, then it's up to you.

Edited April 20, 2010 by dakboy

[+dfx]

power lines have nothing to do with this IMO.

 

a nuvi device by default tries to stick to the roads, so unless you're significantly off the road, it will always show you as being on the road.

 

switch the nuvi to offroad mode and pedestrian navigation mode. that should help. but not that in this setting it's gonna be unusable for regular car navigation, so you're gonna have to switch it back and forth, but can (will) be quite a hassle.

Edited April 20, 2010 by dfx

[+dakboy]

power lines have nothing to do with this IMO.

As the OP specifically mentioned them, I assume he's seeing this happening mostly when he's in close proximity to power lines. I have observed a lot of signal issues in that situation.

[+Chrysalides]

power lines have nothing to do with this IMO.

As the OP specifically mentioned them, I assume he's seeing this happening mostly when he's in close proximity to power lines. I have observed a lot of signal issues in that situation.

I've noticed some signal issues with overhead power lines (the high voltage variety), but not 70m (about 230 ft). Maybe 20 ft.

[+Red90]

The unit (by default) locks to the nearest road. You need to turn routing to "off road".

[+Sarada69]

yes I have it in pedestrian mode and the caches I have trouble with are near power lines...one is beneath a huge cliff. I'm assuming its signal issues.

 

I was between two sets of power lines today and it was all over the map.

[+Sarada69]

power lines have nothing to do with this IMO.

As the OP specifically mentioned them, I assume he's seeing this happening mostly when he's in close proximity to power lines. I have observed a lot of signal issues in that situation.

I've noticed some signal issues with overhead power lines (the high voltage variety), but not 70m (about 230 ft). Maybe 20 ft.

 

The 70m off cache I mentioned also shows you driving off of the road while in driving mode...seems as though the mapping system is off in a certain area here.

[+dfx]

pedestrian mode isn't enough, it needs to be in pedestrian mode AND offroad mode.

[+Jeep4two]

Consider that the zoom levels for a car GPS like Nuvi don't allow for zooming in close enough to see distances to destinations less than the 70m that you refer to. This is one of the primary reasons that in car units that don't have 'geocaching support' (via a compass screen) aren't all that great for caching.

 

If you could zoom in more you would see that you are in fact some distance from the cache according to the map.

 

Watch eBay for a nice entry level eTrex H. I just missed one that went for $29.00 - the photo showed it was an eTrex H, but the seller had the subject and description as just eTrex, causing the bidding to stay low. I had to leave the house and missed the ending. . . bummer.

 

EDIT: to add that the eTrex H usually sells for around $50-80 (sometimes more) and could be had new for between $70 and $80 at many reputable retailers.

Edited April 21, 2010 by Jeep4two

[+Sarada69]

My mother in law has an old handheld...like ten years old. I think it is a Megallen 215...it's mine in June when I see her next. Is that one worth my time or should I buy something more recent?

[+Sarada69]

I ordered an etrex H. Thanks for your help

[+StarBrand]

The general accuracy of most handheld GPS devices is around 15 to 25 feet. Remember though you have might have to add your potential error to any error the cache owner had when placing the cache. That means you could easily find yourself looking for a cache up to 50 feet from where your unit says ground zero is. Most of the time you will find them within 20 feet or less but do be prepared to widen your search. Put the GPS away when you are within 20 feet or so and start looking for likely hiding spots.

 

Back off and re-approach the area if necessary to verify you are looking in the right spot.

[+Redwoods Mtn Biker]

The cliff can impact accuracy due to reflected signals.

[+ecanderson]

The cliff can impact accuracy due to reflected signals.

Ugh. We have one or two of those out here More often than not, it seems to be a big reduction in the # of birds involved in the signal when we get into that situation. Then again, I'm assuming it's not a matter of being between two cliffs (which also happens here - we call them canyons!) where suddenly it's both reflection and poor signal. Makes for some tough finds.

 

Up close to a single cliff face, I've found that, assuming it isn't too horribly tall, backing away from it into a little more clear sky improves the EPE and I can move side to side and triangulate the target against the base of the cliff - assuming you have something with which to triangulate. Backing away from the cliff could actually add reflected signal delay errors, but that's not what happens for me most of the time. Usually, the EPE drops. I've been out 60' or so sweeping back and forth to try to clean up a bearing (using the mag compass to get the bearing - another reason I use that little thing that some people insist shouldn't be turned on!). It's all a matter of trying to work with the local terrain - and that isn't always easy out here, that's for certain.

 

GC14QV0 was a classic case such that I even noted the technique in the log entry to help those that came behind speed the find up a bit.

Edited April 21, 2010 by ecanderson

[+Sarada69]

Oh I've been there twice and even climbed around to the top of the cliff...re-approached several times and think I know roughly where it is and nadda. I bet I'll feel pretty stupid when I do find it. It's new and one other person found it after my first attempt so pretty sure it's there...I'll try again once I get my new GPS...see if there's any diff which I kinda doubt. My current GPS works in most other situations...I started less then a month ago, have 3 babies so I don't get out much and have already found 40. I'm just stuck on two that I can not find.

[+Sarada69]

Got the new GPS, so far so good. Two FTF today and found one I couldn't in the past!