[Proj] Setting up a proj4 specification

[Mikael Rittri]

PS again:

The AFREF newsletter No.5, January 2008,

http://facility.unavco.org/kb/getattachment.php?data=ODR8SkFOIDIwMDggQUZSRUYgbmV3c2xldHRlci5wZGY%3D

publishes what they call a "Molodensky-Badekas 7-Parameters transformation" 
that is "between WGS 84 and Arc 1960 datum for Kenya". I think that means that
the published transformation goes in the direction from WGS 84 to Arc 1960. 
So one would need to reverse the signs of all parameters for use in Proj.4.

Also, I think "Molodensky-Badekas" usually means that the rotation sign
convention is Coordinate Frame Rotation, while Proj.4 uses the opposite 
Position Vector Transformation.  If I am right, the signs of the rotation 
parameters must be reversed once more!  

If I am not mistaken, the Proj.4 syntax for the transformation should be 

   +towgs84=-148.5133,3.4865,-298.0307,-5.9464,7.1414,2.8544,4.3955

Regards,

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


-----Original Message-----
From: Mikael Rittri 
Sent: Wednesday, October 19, 2011 12:55 PM
To: 'PROJ.4 and general Projections Discussions'
Subject: RE: [Proj] Setting up a proj4 specification

PS:

Another datum shift for Arc 1960 to WGS 84 in Kenya is 

   +towgs84=-179.1,-44.7,-302.6

which is probably more accurate. See Clifford Mugnier's column on Kenya, 

http://www.asprs.org/a/resources/grids/06-2003-kenya.pdf

regards,

Mikael Rittri
Carmenta

-----Original Message-----
From: proj-bounces at lists.maptools.org [mailto:proj-bounces at lists.maptools.org] On Behalf Of Mikael Rittri
Sent: Wednesday, October 19, 2011 11:10 AM
To: PROJ.4 and general Projections Discussions
Subject: Re: [Proj] Setting up a proj4 specification

Hello, Hanlie.

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