Using global positioning systems to test extensions of General Relativity

We consider the feasibility of using the Galileo Navigation Satellite System to constrain possible extensions or modifications to General Relativity, by assessing the impact of the related additions to the Newtonian potential and comparing with the available observables: the relative frequency shift and the time delay of light propagation. We address the impact of deviations from General Relativity based on the parameterized Post-Newtonian parameters due to the presence of a Cosmological Constant, of a constant acceleration like the putative Pioneer anomaly, a Yukawa potential term due to massive scalar fields and a power-law potential term, which can arise from Ungravity or f® theories.