I have GPS data at 1 point per second for several weeks in WGS84 latitude/longitude form. It was collected using a UBLOX GPS in 2015 in Australia (Zone 55s)

Would it be correct to use Redfearn's formula to project WGS84 data to Northings/Eastings? Normally it seems that Redfearn's formula is used with GDA94 rather than with WGS84:

I would like to get Northings/Eastings in meters. The data is only accurate to 2-5m at the moment, but I don't want to make it worse so would need to use a conversion that is accurate to within a few cm.

I could just use the ArcMap (ArcPy) projection but since I have very large files (1 point per second) even ArcPy is very slow. Therefore I'd rather put the formula directly into Python. I'll probably use ArcPy later to check some of the results.

The data is collected on animal collars (in Zone 55s). The collars could be used anywhere in Australia (or possibly overseas) so I'd like to use a formula that could be transferable to another part of Australia (although that could involve user input about approximate location).

I've also been investigating how to convert WGS84 (presumably = ITRF2008?) into GDA94 and then to MGA, but this seems very complicated and I think it may be simpler just to work in WGS84 UTM since I don't really need it for an official map.


1 Answer 1


As commented by @mkennedy (who is an Esri projections specialist):

GDA94 and WGS84 basically use the same ellipsoid (it certainly doesn't matter with the accuracy you have), so I certainly don't see any problem.

  • @mkennedy & PolyGeo, thanks! It seems to be working well, really appreciate the help :)
    – Shara
    Commented Oct 31, 2016 at 8:15

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