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Destonian

Converting To Clarke 1880

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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:

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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.gov.za/Surveys/Mapping/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

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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.

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