View Full Version : When not to trust a GPSr



dí76
05-09-2005, 10:33 AM
This has become an ongoing problem with my GPSr. What do you folks think?

All to often I try to find the exact location before I start looking. When I find the location Girlmate has usually already found the cache. When I look at the accuracy of the GPSr it can be usually +/- 20 ft. frequently it is more than a 40 ft radius that the cache is in. I have A Garmin 60c. I wonder if the problem is the operator, Any quick fixes that you suggest and Yes the WAAS is on.

Dave

jdiver3
05-09-2005, 11:49 AM
Give Girlmate the GPSr:D

dí76
05-09-2005, 11:54 AM
Technology stuff and Girls???? I don't know. It might be to complicated:D

WhereRWe?
05-09-2005, 12:14 PM
Technology stuff and Girls???? I don't know. It might be to complicated:D

I agree with Dave1976. The only time RULOST2? gets to hold the GPS is when I need to wander off to water a bush. :eek:

But I have a new GPSMap 60c, and have had results anywhere from DEAd ON to 30 feet away. It just depends on tree cover, etc. :D

Geochicks
05-09-2005, 12:25 PM
Technology stuff and Girls???? I don't know. It might be to complicated:D

HEY!! Don't make me come over there!! :D :p :D

attroll
05-09-2005, 01:09 PM
Here is my ideas on this. The coordinates are only as accurate as the GPS of the person that placed the cache. If he did not get a good set of coordinates then you GPS may be reading right where his might have been wrong or vise versa.

If you have a 60C which is suppose to be a good GPS then maybe the person that placed the cache had a crappy GPS and did not get accurate coordinates.

Nuffer
05-09-2005, 01:26 PM
Of course another alternative once the cache is found is to determine your own coordinates, post information on the geocaching.com site log, invite coroboration, and then come to a consensus as to whether the lats/longs. were correct in the first place or whether your GPS is inaccurate.

WhereRWe?
05-09-2005, 01:28 PM
Here is my ideas on this. The coordinates are only as accurate as the GPS of the person that placed the cache. If he did not get a good set of coordinates then you GPS may be reading right where his might have been wrong or vise versa.

If you have a 60C which is suppose to be a good GPS then maybe the person that placed the cache had a crappy GPS and did not get accurate coordinates.

Good point, and since we've got the new GPS, we've taken both the new and the old out a couple of times and they NEVER agree to within 20 feet.

brdad
05-09-2005, 03:08 PM
I usually try to watch both the GPS and for likely locations about 100 feet before I arrive to a cache site.

If the cache is often more than 40 feet away when you have 20 foot accuracy, something can't be right. We have a few caches with poor coords, but for the most part they are not bad, definitely not 40+ feet bad. I don't even have WAAS and I'm much less than 40 feet more often than not.

Is the datum set right, WGS84? (I would assume it is the default)

If your GPS supports averaging, maybe it's hasn't caught up to you get. I know some Magellan's have this problem, I have heard some slow down when they get about 100 feet away and let the GPS settle so they don't overshoot the area.

We should set up a few areas in the state where reception is good where people can set there GPSr and compare coords. Like on the bird bath at Thomas Hill Standpipe.... Or the first stage of Stacked On StillWater....or maybe we're just better off with the standpipe. :D

Mainiac1957
05-09-2005, 03:42 PM
HA HA :eek:

tat
05-09-2005, 06:57 PM
You are looking at the gps more than girlmate is. While she is getting tracked closer to the cache by staying near you, she is able to pay more attention to those little details. You are spending more time looking at the gps. Or, it could be that she simply has a sharper eye for detail. (I know her obsevation is better than mine!). Try going in separately. I don't think it is your gps or technique.

Beach Comber
05-10-2005, 02:54 PM
I'm with the others on this - there are a number of reasons that you may be experiencing the variability you describe. It will be difficult to narrow it down to a single factor. I have learned to rely on my GPS only so much when I get within 50-100 feet or so - intuition and keen observation will take you a long way as well. Well, those things work for me most of the time - hehehe - unfortunately, I do walk a way with a DNF on occasion, but I am happy to report that it is not as often as it used to be and certainly not of the magnitude of that blasted Old 470 cache - LOL

WhereRWe?
05-10-2005, 05:27 PM
Today, on one of the few times I was at a cache the same time as another cacher, we compared GPS readings. We were BOTH far from the owners readings. I have a very good GPSMap 60C, and they had a basic Gecko - but both were equally far from the owners coordinates.

Go figure... :confused:

Team2hunt
05-10-2005, 08:08 PM
We get close and then I put the GPSr away in my pocket. My navigator has a keen sense of " all things hidden ", and I let him. That's the true spirit of Good Caching. Good luck next trip out. :cool: :cool:

jeannebee
05-10-2005, 09:26 PM
Well, those things work for me most of the time - hehehe - unfortunately, I do walk a way with a DNF on occasion, but I am happy to report that it is not as often as it used to be and certainly not of the magnitude of that blasted Old 470 cache - LOL

So, what about the "blasted old 470? Ever find it? I haven't.

Beach Comber
05-10-2005, 09:32 PM
I am proud to say that I did find it!! Though it took a number of trips and some moral support along the way - LOL. All I can say is that the "hint" that brdad gave me after I struggled for a bit is so very true. "Trust your GPS" If you do and you are diligent about searching in that sport, you WILL find it! My fellow cachers probably tire oof my woes and tales of this cache, but I know that my experience has been "enjoyed" by many! I logged each attempt and needless to say, kept the owner entertained for awhile! Though I joke about the mistery of it, I can also say with complete honesty that I enjoyed the challenge!

brdad
05-11-2005, 06:17 AM
Ye must log every attempt at Old 470 or be cursed by the dreaded DNF Curse! Just ask Tat!
muahahahaha

Better hurry in case the rebuilding of Old 470 requires it be disabled, or worse yet, archived!

Beach Comber
05-11-2005, 06:39 AM
That is so true! I logged all 7 of my DNF's and can happily say that because I did I haven't had to return to a cache that many times since - LOL - or could it be that I just haven't let myself get so obsessed again? hehehehe

tat
05-11-2005, 12:19 PM
The trick is on you! I love DNF's. The sad part of caching is only getting to log once. With DNFs, you can log over and over, again and again.

Actually, this is was my real idea behind Tidal Cache. I wanted to somehow come up with a cache that people would log more than once. Of course, comming up with a wicked good hide is another way! :)