A note on light velocity anisotropy
  It is proved that in experiments on or near the Earth, no anisotropy in the one-way velocity of light may be detected. The very accurate experiments which have been performed to detect such an effect are to be considered significant tests of both special relativity and the equivalence principle 
Bruno Preziosi (Dipartimento di Scienze Fisiche - Universita' Federico   II di Napoli, INFM)