Effect of the Mars’ ionosphere on radio wave propagation. Effect on UHF (0.4 GHz, bottom), S-band (2 GHz, middle) and X-band (8 GHz, top) radio signals. Left: effect on phase delay in centimetres; Right: impact on instant Doppler shift in mHz (assuming dt = 1 s). The red curves correspond to an asset situated in the Northern Hemisphere (E0°, N10°) while the blue curves correspond to the one situated in the Southern Hemisphere (E0°, S10°). The bold, dashed-dots and dashed lines correspond to a LOS elevation of 90°, 55° and 20° respectively (see e the elevation on Fig. 9). The solar activity level is fixed at F10.7P = 120 sfu (moderate solar activity, see Fig. 1).