[Qgis-user] Helmert 7 param transformation

[Stefan Kiefer]

Hi Zoran,
I don't know about Helmert transformation. But if you only need the
description resp. formulas, I believe wikipedia is not a bad place to
start searching:
http://en.wikipedia.org/wiki/Helmert_transformation
>From there you will find some links, nevertheless the internet is a
great place to get more information. I found some hints that you can use
proj4 for helmert transformation, thus it must work with any proj4 based
gis software (qgis is as well as grass). maybe you want to get a deeper
insight of that project, and how to define projection definitions.
http://trac.osgeo.org/proj/
Sorry but that is all I can tell you so far.

cheers

Stefan

Am Montag, den 13.09.2010, 18:50 +0200 schrieb Zoran Jankovic: 

> Hi guys and girls,
> I sent this message once before, but I do not think it got through, so
> I'm reposting.
> 
> 
> I know this is slightly off topic, but I ran out of places to ask...
> I'm looking for a piece of software, it could be a standalone app, or
> some JavaScript somewhere, that can calculate the 7 parameters of
> Helmerts transformation from the coordinates of identical points. Lots
> of applications can transform CRS, even on the fly, but I need
> something to calculate the parameters...
> 
> 
> The thing is I'm preparing for an exam, this is like a bar exam so I
> can get to be a certified surveying engineer, and one of the questions
> is to calculate the params. A decade ago, when I was a student, I had
> the formulas in a Sharp programmable calculator (that I borrowed :-)).
> Alas, both the knowledge, as well as the programmable calculator got
> lost somewhere over the years :-)
> 
> 
> 
> --- 
> Zoran Jankovic
> 
> 
> 
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