The Chatham Islands Transverse Mercator 1979 (CITM1979) is the CIGD1979 projection that has been used for 1:50,000 topographic mapping in the Chatham Islands (the latest editions were published in 1998 with limited revisions).

CIGD1979 projection

The key parameters of CITM1979 are summarised below:

Name:Chatham Island Transverse Mercator 1979
Projection type:Transverse Mercator
Reference ellipsoid:International 1924
Origin latitude:44° 00' 00" South
Origin longitude / central meridan:176° 30' 00" West
False Northing:650,000 metres North
False Easting:350,000 metres East
Central meridian scale factor:1.0000

The CITM1979 has now been superseded by the Chatham Islands Transverse Mercator 2000 (CITM2000) projection. Information about converting coordinates between the CITM1979 and CITM2000 projections is available on the coordinate conversion pages.