Aircraft magnetic declinator system

An aircraft magnetic declinator system comprising:

• an input data bus interface that is connectable to an output of an inertial reference unit in an aircraft, wherein the input data bus interface receives a complementary differential bipolar return-to-zero transmission waveform;
• an output data bus interface that is connectable to an avionics data bus in the aircraft;
• and
• a controller that:
• decodes the complementary differential bipolar return-to-zero transmission waveform to obtain inertial reference data comprising a current position of the aircraft, a true heading, a true track, a magnetic heading, and a magnetic track, wherein the magnetic heading and the magnetic track are determined using magnetic declination data for the current position of the aircraft;
• determines replacement magnetic declination data for the current position of the aircraft from data previously stored within the aircraft;
• determines a replacement magnetic heading and a replacement magnetic track using the replacement magnetic declination data for the current position of the aircraft;
• replaces the magnetic heading and the magnetic track with the replacement magnetic heading and the replacement magnetic track to form adjusted inertial reference data;
• encodes the adjusted inertial reference data to form an adjusted complementary differential bipolar return-to-zero transmission waveform;
• and
• sends the adjusted complementary differential bipolar return-to-zero transmission waveform onto the avionics data bus in the aircraft.

A method for adjusting inertial reference data comprising:

• receiving the inertial reference data from an inertial reference unit in an aircraft, wherein the inertial reference data includes magnetic declination data for a current position of the aircraft;
• determining replacement magnetic declination data for the current position of the aircraft from data previously stored within the aircraft;
• replacing the magnetic declination data of the inertial reference data with the replacement magnetic declination data to form replacement magnetic navigation data for the aircraft at the current position of the aircraft;
• replacing magnetic navigation data in the inertial reference data with the replacement magnetic navigation data for the aircraft to form adjusted inertial reference data;
• and
• sending the adjusted inertial reference data to a number of aircraft systems that use the adjusted inertial reference data during operation of the aircraft.