Systems and methods for the selection of antennas in aircraft navigation systems

A navigation receiver system for an aircraft, the system comprising:

• an RF switch coupled to a plurality of aircraft antennas that receive signals from fixed-location ground transmitters, wherein the aircraft antennas are physically distinct;
• a receiver coupled to the RF switch;
• and
• a processor coupled to the receiver and the RF switch, the processor operating the RF switch to couple one of the plurality of aircraft antennas to the receiver based on calculating an orientation of the aircraft with respect to a direction of one of the fixed-location ground transmitters and simultaneous respective gain patterns for each of the plurality of aircraft antennas,
• wherein operating the RF switch is further based on determining which of the respective gain patterns of the plurality of aircraft antennas provides higher gain in the direction of the fixed-location ground transmitter as determined at least in part from position information for the aircraft and attitude information for the aircraft, and
• wherein operating the RF switch is further based on calculating a vector between the aircraft and the fixed-location ground transmitter, and a rotation of the vector into a frame of reference in which the respective gain patterns are mapped.

An aircraft navigation method, the method comprising:

• determining coordinates of a ground station;
• determining a direction of the ground station with respect to an aircraft reference frame for a first position of an aircraft traveling along a flight path;
• determining which of a plurality of antennas aboard the aircraft has a desired gain pattern in the direction of the ground station, wherein the antennas are physically distinct and simultaneously receiving, wherein determining which of the plurality of antennas aboard the aircraft has a desired gain pattern in the direction of the ground station is based on an orientation of the aircraft relative to the ground station as determined at least in part from position information for the aircraft and attitude information for the aircraft, wherein determining which of the plurality of antennas aboard the aircraft has a desired gain pattern in the direction of the ground station includes calculating a vector between the aircraft and the ground station, and a rotation of the vector into a frame of reference in which gain patterns of the plurality of antennas are mapped;
• and
• switching a radio to use the antenna having the desired gain pattern.