The response of a low-field side X-mode reflectometer system for ITER is simulated with a 2D reflectometer code using a realistic plasma equilibrium. Relativistic corrections to the plasma permitivity due to the high electron temperature were included. It is found that the reflected beam will often miss its launch point by as much as 40 cm and that a vertical array of receiving antennas is essential in order to observe a reflection on the low-field side of ITER. Relativistic absorption effects were studied with a 1D full wave code and found to be insignificant for reflections from the low-field side up to the plasma centre.