Receivers from various manufacturers are operated in parallel to reduce the characteristic receiver noise error.

The difference between signals transmitted on the L1 and L2 frequencies are processed by the receiver todetermine an error correction.

Signals from satellites are received by 2 different antennas which are located a fixed distance apart. Thisenables a suitable receiver on the aircraft to recoanise and correct for multipath errors.

Fixed ground stations compute position errors and transmit correction data to a suitable receiver on theaircraft.