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Roaman
14th December 2003, 09:53 AM
First time I have posted here so HELLO to to all.
Now my problem - I have just got a GPS, a Magellen Map 330, and am just starting to geocache. I located a cache yesterday, with difficulty, having found it via the hints and photos. I found my GPS was showing, at best, 35ft and at worst about 100 ft off target. It was under confirs but they were not too dense, I could see clear sky, and it was showing 4/5 satallites.
Is this normal?
Do I have a problem with my machine?
Is there a better, reasonably priced GPS?
I know, so many questions but any help would be gratefully received.

Peter

minstrelcat
14th December 2003, 04:04 PM
I would say that what you are seeing is perfectly normal. Even in ideal conditions, any GPS is only accurate to about 5-10 metres. Under tree cover (and the GPS system was never designed to operate in these conditions), accuracy can suffer more. Who ever took the cache coordinates in the first place would have had the same problem - add their error to yours, and you could be way off. All part of the challenge of geocaching.

If you are under tree cover, try turning the GPS off and back on (so that it has to re-acquire the satellite signals) and see if you get a different reading. With practice, you will get a 'feel' for when the GPS is telling the truth...

In terms of the MAP 330, I use one and reckon it is better than many for performance under less than ideal conditions and a very good unit for geocaching. I'd rate it more highly than the more popular eTrex... have a look at:

http://gpsinformation.net/main/gpshiking.htm

Adam.

Team Minstrelcat Technical Support :rolleyes:

BugznElm'r
14th December 2003, 05:58 PM
At the core, GPS receivers are much the same. The receiver itself is but a very small part in a massive, global system. OK, different receivers have different bells and whistles (mapping, barometers, games and so on) but all-in-all, from an accuracy point of view, they work the same.

I wouldn't even get too caught up in the antenna debate either (quad helix vs. patch). Having used both types extensively through different models I have yet to see much of a difference as long as you hold them right.

Geocaching is about a lot more than being led to a cache by an electronic device :D If you get interested and good at tracking you can switch off the device when you are within 50 m of the cache in most areas :)

Here are some of our ideas for navigating the final 20 m ...Final 20 m (http://www.kingsley-hughes.com/outdoors/gps/final_20m.htm)

Happy caching!

Brenin Tegeingl
14th December 2003, 07:08 PM
Carry a compass, for when you're close to the cache but are having reception problems. When you are about 50m away, go to the page on the GPSr which shows the bearing to the cache. Using this, sight a easy to see object along the bearing, move to a different position and repeat. Were the two bearing lines cross will put you in the general area of the cache. This has worked each time I've used this method. You can pick up a decent compass for about £10, and they never need batteries :D. Warning, this method only works as long as you remember to carry the compass :( . Dave

BugznElm'r
14th December 2003, 07:43 PM
I'd also add that as well as a compass, a good map really helps ... paper maps are OK but nothing beats the electronic maps. Let's you know what to expect and plan a route. :D

Oh, and add to that a Pocket PC ... :P

And a wheelbarrow to carry all the kit and batteries!

John Stead
15th December 2003, 11:59 PM
Thanks a lot BugznElm'r - I've been at this game now for two and a half years and have never seen such a clear explanation of technique in cache hunting. I think I have learned most of your tips the hard way but it is great to see it set out so well and I am sure I have learned some more from your articles.
Now all I have to do is apply them and it will all be a doddle - or will it?
Would you care to offer your articles to the powers that be for publication?

Paul G0TLG
16th December 2003, 12:27 PM
Originally posted by BugznElm'r@Dec 14 2003, 05:58 PM
Here are some of our ideas for navigating the final 20 m ...Final 20 m (http://www.kingsley-hughes.com/outdoors/gps/final_20m.htm)
BugznElm'r, this is a great page! I've taken the liberty of linking to it from a page for which I'm webmaster.

Go to www.swhantsraynet.org.uk, then "for our members" and "training packages"...if you object to the link, please let me know and I'll remove it forthwith.

All the best

Paul

Roaman
16th December 2003, 12:55 PM
:D Well what can I say, except thanks to all who have replied. I feel reasured AND informed. I have orienteered in the past and most of the techniques are familier to me and I do have a compass (must remember to take it with me in future).
Many thanks to all

Peter

Pharisee
16th December 2003, 01:53 PM
Originally posted by Roaman@Dec 14 2003, 09:53 AM

<CLIP>......I could see clear sky, and it was showing 4/5 satallites.
Is this normal? ........</CLIP>

To get a reading on 5 or 6 satellites is about average for most situations. Hills that obscure the horizon and woodland that obscures just about everything is the norm for geocaching. Only at this cache (https://www.geocaching.com/seek/cache_details.aspx?guid=bac3f4a1-6656-441c-86e7-f72be0e9e583) did I get a good DGPS lock on all visible orbiting satellites and get an estimated error of about 6 feet. It is way up on a hill though and the nearest tree was miles away :)

BugznElm&#39;r
17th December 2003, 03:47 PM
Originally posted by Paul G0TLG@Dec 16 2003, 12:27 PM
BugznElm&#39;r, this is a great page&#33; I&#39;ve taken the liberty of linking to it from a page for which I&#39;m webmaster.

Go to www.swhantsraynet.org.uk, then "for our members" and "training packages"...if you object to the link, please let me know and I&#39;ll remove it forthwith.

All the best

Paul
Thanks for the link Paul&#33;&#33;&#33; :D