Basic GPS setup for a Newbie in the UK

[+woodhst2]

Hi All

 

Just a quick question or two about basic GPS setup (I have a "pre-owned" basic etrex). I have set hddd.mm.mmm and having found myself some 100m or so "out" a few times I've finally worked out that I should be using WGS84 (not "ord srvy GB"). At least I think so. But may I ask if it matters what you set in "north ref" i.e. true, magnetic or grid? And then there's "variance" - what do you do with that?

 

If I go back to "British Grid" should I switch back to "ord srvy GB" or do I leave that as WGS84?

 

Thanks for you patience... all I want to do is "get out there" - it's too early for me to get too technical.

 

Steve

[+lordelph]

Use WGS84 and DD MM.MMM format for caching - I believe the north reference is only used to allow the unit to figure out how to present your heading, i.e. if you walk towards a waypoint, should it say your direction is e270 degrees or 276 degrees?

[Edgemaster]

For coordinate entry from the geocaching site, the GPS should generally be set to hddd mm.mmm', WGS84.

In general, you should never have hddd mm.mmm' set with Ord Srvy GB.

 

If you wish to view your current location as an OS Grid Reference, set position fmt to British Grid, it will force the second to Ord Srvy GB, which it should be (and cannot be changed from).

 

I have just left my north ref/variance settings to the defaults (Mag/003). I have no reason to change them.

[fraggle69]

Make sure you have WASS enabled in the system menu. This should get you closer to the cache, also check the software is upto date by visiting the garmin website. I don't find the yellow etrex that great under tree cover!!

 

Aii

[+GeoCornetto]

Make sure you have WASS enabled in the system menu.

Aii

 

WAAS is anly available in North America. Ive found I get better results with it turned off plus it saves battery life.

 

Ive found walking slower in wooded areas keeps the signal up. The yellow eTrex is slow to update itself. Once you get into the woods, slow down, take it easy

[+scottpa100]

Make sure you have WASS enabled in the system menu.

Aii

 

WAAS is anly available in North America. Ive found I get better results with it turned off plus it saves battery life.

 

Ive found walking slower in wooded areas keeps the signal up. The yellow eTrex is slow to update itself. Once you get into the woods, slow down, take it easy

 

Yes WAAS is only available in north America, but there is EGNOS the European version which should be picked up by WAAS enabled handsets. Though I'm saying this and its all theoretical, does anyone know if EGNOS works and if it has made a substantial difference on their accuracy?

[+scanker]

I think EGNOS improves accuracy - when my GPS displays the Ds in the satellite bars the accuracy is normally then about ±3m.

[+woodhst2]

Many thanks to you all for your prompt assistance - much appreciated

 

I too think the yellow etrex is a little sloooow and weak under trees, but hey, it only cost me £50 on eBay and was virtually new. I only wanted it originally to stop getting lost on long walks (often from camp sites) but then found this Geocaching stuff and ... well ... I've sort of got hooked ... a bit ... nothing I can't handle, right??

[+Team Sieni]

If I have a clear view of the sky to the south and lots of satellites I often get "D"s (for differential - (ie WAAS/EGNOS) on the signal strength bars, and the unit shows pretty small error <= 6m. Whether it really is more accurate, I can't say. (Garmin GPSMap 76S)

[Helen in Mustardland]

If you have a pre-owned Yellow Etrex, and you have to set the datum and co-ord type separately, it probably doesn't have the WAAS thing anyway. Mine didn't until I sent it back to Garmin to get the rubber band round it changed when the glue gave up, and they sent me a whole new unit which sets the datum all by itself and has lots of other scary features like open and closed cache icons (though I still use fish for old-times sake) and that WAAS thing, which I've never used, and the backlight's got jaundice.

[+The HERB5]

Changing the coord system doesn't correct already entered points.

 

They need to be re-entered.

 

 

I think

[Deceangi]

From the original comment that the Yellow is out by 100m, I'd say you've not reset the Map Datum from OS GB. This is common error seen by Reviewers.

 

Position Format: hddd°mm.mmm

Map Datum: WGS 84.

 

The only waypoints that might need changing are those taken in the field, any entered by hand will be correct.