équipement de superstructure

CONT: The above deck equipment is usually some form of tracking dish, with a circular polarized feed arrangement. This usually takes the form of an helical antenna, wound with left-hand circular polarization. The signal from the satellite is right-hand circular polarization, but since the signal is reflected by the dish, polarization sense is reversed. This is the same principle as if you were to look in a mirror; your image is reversed.
OBS: Inmarsat satellite.