Groundspeak Forums: Converting To Clarke 1880 - Groundspeak Forums

Jump to content

Page 1 of 1
  • You cannot start a new topic
  • You cannot reply to this topic

Converting To Clarke 1880

#1 User is offline   Destonian 

  • Tadpole
  • Group: Members
  • Posts: 1
  • Joined: 04-July 04

  Posted 14 February 2005 - 12:54 AM

Hi, does anyone have a tool (software) that would be able to convert WGS84 coords tothe Clarke 1880 datum used on the older SA maps?

I owuld like to try and use the old map and compass for my next few cache searches. Thanx in advance! :lostsignal:

#2 User is offline   Azaruk 

  • Geocacher
  • Group: Members
  • Posts: 445
  • Joined: 29-May 04

Posted 14 February 2005 - 02:41 AM

I would be interested in this too........

#3 User is offline   Stefanoodle 

  • Geocacher
  • Group: Members
  • Posts: 50
  • Joined: 24-September 02

Posted 14 February 2005 - 08:15 AM

Is the Clarke 1880 the same as the Cape co-ordinate system? I seem to recall Cape is referenced to Clarke. If so, your GPSr may be able to convert for you if you set the datum as Cape. My GPS unit has that datum.

I think programmes like OziExplorer may also have Clarke 1880 as a possible datum. If I find out more, I will post here.

Alternatively, you could contact the Department of Land Affairs, Chief Directorate of Survey and Mapping, in Mowbray. They have a website http://w3sli.wcape.gov.za too.
This might be quite useful too: http://w3sli.wcape.g...pping/wgs84.htm

They do have software to convert between Gauss conform, WGS84 and Bessel. I don't recall whether or not it also could work from/to Clarke.

good luck

#4 User is offline   Jors 

  • Caching since 17 January 2001
  • Group: +Premium Members
  • Posts: 364
  • Joined: 14-January 01

Posted 15 February 2005 - 12:22 PM

Is the Clarke 1880 the same as the Cape co-ordinate system?
--Yes it is.

I seem to recall Cape is referenced to Clarke. If so, your GPSr may be able to convert for you if you set the datum as Cape. My GPS unit has that datum.
--True

I think programmes like OziExplorer may also have Clarke 1880 as a possible datum.
--Yes Ozi does, it's called Cape datum.

Dept of land affairs do have software to convert between Gauss conform, WGS84 and Bessel. I don't recall whether or not it also could work from/to Clarke.
--Gauss Conform is the projection based on the Clarke 1880 mod ellipsoid, so the software should handle that. (last time I looked, the price was R50-00)

But, if you decide to use the Lat-long coordinates in WGS84 on a Cape datum map, in Gauteng, you will only be about 2 seconds out in latitude, which relates to about 60 meters on the ground, which again relates to about 1mm on a 1:50 000 topo map. You can verify this too by switching datums between Cape and WGS84 on your GPSr.

Hope this helps somewhat.

Share this topic:


Page 1 of 1
  • You cannot start a new topic
  • You cannot reply to this topic