[Proj] Gauss conformal Lo33 on Clarke 1880 Cape Datum to WGS84 UTM36S - NTv2 file needed.

[Mikael Rittri]

Hello again Zoltan.

I wrote:

> As a last resort, if you have more examples of source and target points that are representative for your area of interest,
> one could use the SEVENPAR program from Killetsoft to compute a local 3-parameter or 7-parameter transform.

Actually, it is possible to use Proj.4 to compute a local 3-parameter transformation from
your single test point, but I have no idea how accurate it would be for the rest of your data.
By assuming the same height above the ellipsoids for your test point, I get the 3-parameter
transform

    +towgs84=-144.47,-128.70,-288.68

which is tailor-made for your single test point, so:

 > cs2cs +proj=tmerc +lon_0=33 +a=6378249.145 +b=6356514.966398753 +towgs84=-144.47,-128.70,-288.68 +to +init=epsg:32736

 -49717.410    -2872274.540

 450273.23     7128571.66    0.00


Best regards,

Mikael Rittri
Carmenta
Sweden
http://www.carmenta.com

________________________________
From: proj-bounces at lists.maptools.org [mailto:proj-bounces at lists.maptools.org] On Behalf Of Mikael Rittri
Sent: Tuesday, August 28, 2012 4:20 PM
To: PROJ.4 and general Projections Discussions
Subject: Re: [Proj] Gauss conformal Lo33 on Clarke 1880 Cape Datum to WGS84 UTM36S - NTv2 file needed.

Hello Zoltan,

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