Using D3 to transform NZTM2000 coordinates to WGS84

Question

I've been trying to convert some NZTM2000, a variaton of the Transverse Mercator projection used in New Zealand (http://www.linz.govt.nz/data/geodetic-system/datums-projections-and-heights/projections/new-zealand-transverse-mercator-2000) to WSG84 lattitude/longitude coordinates without success.

The NZTM2000 specs says the TM is configured with the following parameters:

Origin latitude: ° 00' 00" South
Origin longitude / central meridan:173° 00' 00" East
False Northing:10,000,000 metres North
False Easting:1,600,000 metres East
Central meridian scale factor:0.9996

I tried to use them in S3:

var projection = d3.geo.transverseMercator()
    .rotate([origin_lat, origin_lng])
    .scale(scale_factor)
    .center([false_northing, false_esting])

(among other ways).

I was using an small data subset with known WGS84 values:

NZTM2000                WSG84
---------------------   -------------------------------
Norting     Easting     Latitude        Longitude
5771280.5   1900560.5   38 09 22.691 S  176 25 48.538 E
5771280.5   1900570.5   38 09 22.679 S  176 25 48.948 E
5771280.5   1900571.5   38 09 22.678 S  176 25 48.989 E
5771280.5   1900572.5   38 09 22.677 S  176 25 49.030 E

Any help?

Thank you so much

Thanks! I'll read the post and examples posted there and write back here my conclussions. — rgrocha
This looks like a question that may fare better if deleted from here and is re-asked at Geographic Information Systems (it is too old to migrate). — PolyGeo
@rgrocha I have a question, based on the example above what values did you chose for false_northing and false_easting? Did you convert metres to something? — arunkjn

rgrocha rgrocha · Accepted Answer · 2016-01-12T17:58:32

I finally found a solution LINZ site. They have already the algorithm coded in C at http://www.linz.govt.nz/data/geodetic-services/download-geodetic-software#nztm2000.

And then again, someone ported it to C# at https://github.com/leighghunt/nztm/blob/master/nztm/nztm.cs.

I ported this latest version to JavaScript and it worked just fine.

Send me a message if you want my version.

========= can you share the Javascript version in github please? i really need it

Using D3 to transform NZTM2000 coordinates to WGS84

1 Answers