One embodiment is directed towards a method (200) for determining a heading for a hybrid navigation system with magnetometer aiding. The method includes receiving signals (202) from a plurality of GNSS satellites, obtaining three-dimensional inertial measurements (202) from one or more inertial sensors, and obtaining three-dimensional magnetic measurements (202) from one or more magnetometers. Magnetic bias states (204) are estimated for the three-dimensional magnetic measurements with a magnetic calibration filter using the three-dimensional inertial measurements, data from the signals from the plurality of GNSS satellites, and the three-dimensional magnetic measurements. An artificial heading (206) is calculated based on the magnetic bias states. A main navigation solution (208) can be estimated with a main navigation filter using the three-dimensional inertial measurements, data from the signals from a plurality of GNSS satellites, and the artificial heading.