Abstract: Systems and methods for determining magnetic heading information for a vehicle. In one example, the system identifies at least one polar exclusion area based on predefined rate-of-change of magnetic variation (magvar). Locally stored magvar information is retrieved based on received vehicle position information that is outside the polar exclusion areas. Magnetic heading is determined based on the retrieved magvar information, the received position information, and the received true heading information. In another example, the magnetic heading is determined based on the retrieved magvar and magvar rate-of-change information, on the received vehicle position and true heading information, and on the received date information. In another example, the magnetic heading is determined based on the received vehicle position, true heading, and date information, and on the magvar retrieved from a world magnetic model utilizing stored model coefficients.

Abstract: Systems and methods for determining magnetic heading information for a vehicle. In one example, the system identifies at least one polar exclusion area based on predefined rate-of-change of magnetic variation (magvar). Locally stored magvar information is retrieved based on received vehicle position information that is outside the polar exclusion areas. Magnetic heading is determined based on the retrieved magvar information, the received position information, and the received true heading information. In another example, the magnetic heading is determined based on the retrieved magvar and magvar rate-of-change information, on the received vehicle position and true heading information, and on the received date information. In another example, the magnetic heading is determined based on the received vehicle position, true heading, and date information, and on the magvar retrieved from a world magnetic model utilizing stored model coefficients.