Hi,
I am using OS data to digitise agricultural field polygons and then obtain their areas
in Mapinfo.
I believe you should use Options/Preferences/Map Window and select the Cartesian
Distance/Area option.
Good luck
Rod Ellis
GIS Unit
ADAS Aberystwyth
Tel 01970 621438
Fax 01970 617798
Email [EMAIL PROTECTED]
>>> Ian Macey <[EMAIL PROTECTED]> 09/23/99 10:46am >>>
I have been using the spherical algorithm to calculate the area of field
polygons since upgrading to MI Pro 5.5. Is this the correct way for use with
Ordnance Survey data which is tied in to the British National Grid? The
reason that I ask is because I have been sent and Arc View shape file where
the person quoted the area as 546.01 ha. This is the area that I get when
using the cartesian algorithm. When using the spherical option I get an area
of 544.48 ha which is causing some contention.
Also how should these compare with the traditional ways that the OS use
calculate their areas on old paper plans.
Any help is much appreciated
IAN
---------------------------------------
Ian Macey
Dreweatt Neate
mailto:[EMAIL PROTECTED]
http://www.dreweatt-neate.co.uk
Telephone: 01635 263050
Facsimile: 01635 263090
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