GPS Setting

[Guest weenantie]

I now have my GPS unit.....I am sure I read somewhere on here....that the settings for the UK...were different from those used in the USA......I can't remember what it was about....can anyone help ??

[Guest welch]

quote:

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Originally posted by weenantie:

I now have my GPS unit.....I am sure I read somewhere on here....that the settings for the UK...were different from those used in the USA......I can't remember what it was about....can anyone help ??

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ive never heard of this but its possiable. your talking about more than the metric/standard thing right?

shearch the old theards for info.

[Guest Moss Trooper]

What your probebly refering to is the difference in grid references and datums. In UK we use OSGB Gridreference and Datum (the point where the 0,0 of the grid refrence occurs)

 

In USA thay have different datums, indeed most countrys have their own system. For Geocaching purposes the standard is DD MM.MMM Lat/Long and WGS84 Datum for world wide use. If you want to tie this up with an OSGB Map. Explorer/Landranger maps etc then you need to convert this. The simplest way is to have the waypoint in your GPS and set the GPS to use British Grid and Ord Sury GB Datum.

 

Hope this helps.

 

Moss de Boss sorta

 

[This message has been edited by Moss Trooper (edited 04 January 2002).]

[Guest Moss Trooper]

What your probebly refering to is the difference in grid references and datums. In UK we use OSGB Gridreference and Datum (the point where the 0,0 of the grid refrence occurs)

 

In USA thay have different datums, indeed most countrys have their own system. For Geocaching purposes the standard is DD MM.MMM Lat/Long and WGS84 Datum for world wide use. If you want to tie this up with an OSGB Map. Explorer/Landranger maps etc then you need to convert this. The simplest way is to have the waypoint in your GPS and set the GPS to use British Grid and Ord Sury GB Datum.

 

Hope this helps.

 

Moss de Boss sorta

 

[This message has been edited by Moss Trooper (edited 04 January 2002).]

[Guest weenantie]

Thanks Moss Trooper.....I think that is exactly what I was reading........it was a while ago.......so I wasn't sure what it was all about...thanks for your help.

 

Thanks also to Welch for your input.

[Guest jeremyp]

t to it is zero and it is currently quite close to the meridian defined by OSGB36. The whole of Great Britain is actually moving very slowly North East so you'd better find those caches soon before the coordinates get too far out :-)

 

In this country a lat/long in WGS84 is roughly 100 metres(ish) away from the same lat/long in OSGB36.

 

Anyway, all the coordinates on the Geocaching web site are WGS84 so make sure that is the datum that is set if you enter them manually into your GPS unit. If you use EasyGPS to upload them to your unit you don't need to worry, as uploads are always in WGS84 format (at least on a Garmin eTrex). If you then decide to plot the coordinates on a map, find out what datum it uses (it'll be printed on the map) and change your GPS unit to use that datum. The coordinates on the GPS will automatically be corrected for you before being displayed.

 

This web site:

 

http://www.gps.gov.uk/guidecontents.asp

 

is an unbelievably good introduction to the subject of GPS datums.