[Proj] trying to understand results of reprojecting from epsg4326 to epsg 31370

[OvV_HN]

----- Original Message ----- 
From: "Moritz Lennert" <mlennert at club.worldonline.be>
To: "PROJ.4 and general Projections Discussions" <proj at lists.maptools.org>
Sent: Thursday, July 09, 2009 9:12 AM
Subject: Re: [Proj] trying to understand results of reprojecting from 
epsg4326 to epsg 31370


....

>> In the pdf article found under
>> "Transformaties tussen geografische cöordinaten (φ,λ) en vlakke 
>> coördinaten
>> (x,y) voor Lambert 1972 en 2008."
>> on the page
>> http://www.ngi.be/NL/NL2-1-7.shtm
>> everything regarding rotation models, signs, errors wrt the Lambert 1972
>> projection is clearly explained.
>> It is possible that there is also a French version of that article
>> available.
>
> I'm sorry, but I don't see where in this document I can see a hint about
> different geodetic conventions concering the sense of rotation, be it in
> the Dutch or the French version...
>
> Moritz


So sorry; to me the following line said it all:

"De 7 parameters welke door het NGI worden gepubliceerd (tabel-1) steunen op 
de
‘Coordinate Frame Rotation’ conventie ; als men gebruik maakt van de 
‘Position Vector’
conventie, moet het teken van de drie rotatieparameters veranderd worden 
(tabel-2)."

For the non-Dutch reading audience watching this game from the bleachers a 
translation:
<<The 7 parameters published by the NGI (Table 1) are based on the 
coordinate frame rotation convention; if one uses the position vector 
convention, change the sign of the 3 rotation parameters (Table 2).>>

Oscar van Vlijmen.