Emailing mit dem Ordnance Survey ...
From: sales@ordsvy.gov.uk
To: postmaster@explorermagazin.de
Subject: RE: Digital Map Scotland
Wed, 06 May 1998 14:49
We have a CD-ROM called the Interactive Atlas of Great Britain. This is available at a Single User Licence cost of £39.99 Inc VAT. This has National Coverage at 1:6,000,000 down to 1:250,000. There are also 45 town & city plans including Central London. And more than 300 media pin hotspots illustrating cultural, historical and architectural sites with pictures, videos, landscape models and larger scale mapping,
Regards
Tony Llewellyn
From: postmaster@explorermagazin.de
To: dighlpdesk@ordsvy.gov.uk
Subject: Interactive Atlas of Great Britain
Date: 17 June 1998
13:11
Hello,
we have purchased the CD-ROM with the Atlas and we think that this is an excellent product for tourists. To use it together with our GPS we would like to know which MAP DATUM is used for the longitude/latitude reference (WGS84, Ordnance Survey, ...?) and which grid (British Grid, ...?). Is it possible to give us some information?
Thank you for your help.
Regards
J. de Haas
From: rprior@ordsvy.gov.uk
To: postmaster@explorermagazin.de
Subject: Ordnance Survey Interactive Atlas of Great Britain
Date: Wed, 17 Jun 1998 16:47
Dear Mr de Haas.
Thank you for your e-mail which has been forwarded to me from our Sales Desk. I can give you the information you ask for on the understanding that you will reply (direct to me, details below) with more information regarding your proposed use of the product.
As you know, the Interactive Atlas of Great Britain tracks cursor position by either National Grid or latitude/longitude references. The grid used in the product is the Ordnance Survey National Grid which, I have been informed, is based on WGS84. The latitude/longitude references are calculated from the National Grid references.
My questions are as follows: How, technically, are you proposing to use the Interactive Atlas and your GPS together? There is no way of getting grid references or lat/long out of the product other than reading it off screen. I am also slightly concerned about the licencing issues; you mention tourists but I suspect that you have purchased a single user licence which should therefore only be used for your own personal use. Please can you reply with a detailed description of what you are proposing.
I hope the information supplied is useful and that you can forward the information I have requested, ideally before 23rd June - I am on holiday from this date until 12th July.
Thank you for your interest in Ordnance Survey, the National Mapping Agency of Great Britain, and our Interactive Atlas of Great Britain product in particular.
Best wishes,
Richard Prior
Electronic Products Developer & Designer
RE&L - Electronic
Products
Room C652
Ordnance Survey
Romsey Road
SOUTHAMPTON
SO16 4GU
United Kingdom
From: postmaster@explorermagazin.de
To: rprior@ordsvy.gov.uk
Subject: Interactive Atlas, your e-mail of Wed, 17 Jun 98
Date:
18 June 1998 10:36
Dear Mr Prior,
thank you very much for your reply.
There is no reason for you to be concerned about licencing issues, because I only was of opinion that the Atlas is an excellent product for tourists. We are a single tourist couple with a single GPS and a single user licence and are preparing our vacation in Great Britain by plotting routes on a single laptop in a single car.
I guess there is no other way for us to get the coordinates from the Atlas than reading it off screen and enter our waypoints into the GPS. If it works, we will write a report about the tour in our (non commercial) outdoor internet magazine EXPLORER.
Our problem with the grid reference of the Atlas is as follows:
EXAMPLE: Harbour of Southampton, taken from the Atlas: Latitude/Longitude:
50°53,6´N 001°24,4´W; Grid: SU 417 105.
After
entering the waypoint with Lat/Lon into my GARMIN with Map Datum WGS84,
I get as BRITISH GRID: Zone SU, Easting 417 29 mt, Northing 110 74 mt,
what is about SU 417 110.
After entering the same waypoint with Lat/Lon into the GPS with Map Datum ORDNANCE SURVEY, I get the following BRITISH GRID: Zone SU, Easting 417 25 mt, Northing 106 57 mt, what is about SU 417 106.
As this example demonstrates, I get the better results with Map Datum ORDNANCE SURVEY instead of WGS84, but there are even bigger differences in other parts of the country.
As I suppose that the Garmin conversion Lat/Lon -> British Grid works correct, I have no explanation for the differences. Perhaps it is possible for you to find out what the reason is and to solve the problem.
Thank you very much for your interest in our problem and your support again.
Best regards
Juergen de Haas
From: rprior@ordsvy.gov.uk
To: postmaster@explorermagazin.de
Subject: RE: Interactive Atlas, your e-mail of We
Date: Fri,
19 Jun 1998 15
Juergen.
Thank you for your e-mail explaining your use of the Interactive Atlas; I have no problems with you using the product for the described purposes.
Regarding your datum query, I think the reason why the 'Ordnance Survey' option gives better results is because it is calculating using the OSGB36 datum on which all OS maps are based on - I'm sorry but I told you the wrong datum in the first place! The difference between Ordnance Survey (OSGB36) and WGS84 is that the Ordnance Survey option is, in effect, a local datum to Great Britain whereas WGS84 is a worldwide datum which is why the variations between grid references are different for different areas of the country.
I hope the above is help and that you enjoy using the Interactive Atlas and your trip to Great Britain.
Thank you once again for your interest in Ordnance Survey.
Best wishes,
Richard Prior
Electronic Products Developer & Designer
RE&L - Electronic
Products
Room C652
Ordnance Survey
Romsey Road
SOUTHAMPTON
SO16 4GU
United Kingdom
