A system is described for the geometrical calibration of the planned PROBA-V multi spectral earth observation satellite. The largest challenge lies in the complex thermo-elastic distortion due to the absence of active thermal control onboard. The system is based on a 2 step (first by scene, then by global trend), weighted and constrained least squares inversion model. The geometric reference dataset consists in a set of automatically selected image chips from the Geocover 2000 dataset. Results show that the sub-pixel absolute localization accuracy requirements should be reached.