[Proj] +towgs84 approximation error

[Jochem]

Hi Martin,

Indeed it would be better to give people using the approximated formulas an
error than for the people that use the strict ones.

The "late-binding" will not solve these problems, since also for parameters
between system A and B the rotation angles are too large for the approximate
formulas:

In my case:

Frame A -> WGS84
-294.1985,231.0171,-285.2462,-11.34441,40.54620,-9.73364,15.7901

WGS84 -> Frame B
270.4047,-127.0720,286.7425,+11.13087,-1.67806,-24.24971,0.4536

Frame A - > Frame B
-23.764,103.995,1.506,-0.21346,38.86867,-33.98116,16.2437
NB: I did not simple add the parameters, but used strict formulas to combine
them.

Therefore, I'm still convinced that the formulas of +towgs84 should be
corrected.

Regards, Jochem




--
View this message in context: http://osgeo-org.1560.x6.nabble.com/towgs84-approximation-error-tp5313738p5313855.html
Sent from the PROJ.4 mailing list archive at Nabble.com.