Home PageFacebookRSS News Feed
PocketGPS
Web
SatNav,GPS,Navigation
Pocket GPS World - SatNavs | GPS | Speed Cameras: Forums

Pocket GPS World :: View topic - Best datum for geocaching/ord survey
 Forum FAQForum FAQ   SearchSearch   UsergroupsUsergroups   ProfileProfile   Log in for private messagesLog in for private messages   Log inLog in 

Best datum for geocaching/ord survey

 
Post new topic   Reply to topic    Pocket GPS World Forum Index -> Beginners GPS Lounge
View previous topic :: View next topic  
Author Message
JACK2008
Occasional Visitor


Joined: Aug 17, 2008
Posts: 1

PostPosted: Fri Mar 26, 2010 4:16 pm    Post subject: Best datum for geocaching/ord survey Reply with quote

Hi
I am running Garmin Xt, Memory Map (trial) and Oziexplorer.

With Garmain and Memory map I get the same grid reference so the site i'm at, but I really wnt to use Oziexplorer but it seems to be 100m or so metres out when compared. I have tried all the datums/projections without luck.

What is the best datum and projection to provide a OS grid reference on OZiexplorer.

Thanks
Back to top
View user's profile Send private message
jolly47roger
Regular Visitor


Joined: Jan 11, 2008
Posts: 116

PostPosted: Mon Mar 29, 2010 6:15 pm    Post subject: Reply with quote

In OZI on a PC you need to set the grid to 'BNG' and the Datum to 'Ord Srvy Grt Britn' (right click on the items in the bar above the map display)

You might like GPSU, too, for handling tracks and routes.
Back to top
View user's profile Send private message
philpugh
Lifetime Member


Joined: Dec 28, 2005
Posts: 2003
Location: Antrobus, Cheshire

PostPosted: Fri Apr 09, 2010 8:39 pm    Post subject: Reply with quote

Just to clarify the previous reply.

For OZIExplorer you need to set the datum of your GPS to the same as that which the map was created with. If it is an OSGB map then it probably will be OSGB 36 and transverse Mercator projection. The 100m or so error seems right for a OSGB map being used with WGS84 datum (the usual default datum). YOu can calibrate a scanned map image to any datum with OZIExplorer - assuming you know three co-ord positions in the relevant datum.

The .map file that will be with the OZI mapping file should be readle with a standard text editor and includes the datum and the calibration points also.

EDITED TO INCLUDE: Geocaching information is usually supplied in WGS84 datum as this is the defacto international standard.
_________________
Phil
Back to top
View user's profile Send private message







Posted: Today    Post subject: Pocket GPS Advertising

Back to top
Display posts from previous:   
Post new topic   Reply to topic    Pocket GPS World Forum Index -> Beginners GPS Lounge All times are GMT + 1 Hour
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Make a Donation



CamerAlert Database

Click here for the PocketGPSWorld.com Speed Camera Database

Download Speed Camera Database
22.034 (27 Mar 24)



WORLDWIDE SPEED CAMERA SPOTTERS WANTED!

Click here to submit camera positions to the PocketGPSWorld.com Speed Camera Database


12mth Subscriber memberships awarded every week for verified new camera reports!

Submit Speed Camera Locations Now


CamerAlert Apps



iOS QR Code






Android QR Code







© Terms & Privacy


GPS Shopping