A high performance inertial system that includes magnetometers can provide accurate platform heading information in a variety of applications and operational environments. The key components of these systems include magnetometers to measure the Earth’s local magnetic field, accelerometers to determine tilt, and gyroscopes to determine rotation of the system. Together these sensors provide the data that can be processed to accurately calculate platform attitude and heading. Magnetometers are susceptible to measurement distortion in the presence of any magnetic material that may change the intensity or direction of the Earth’s magnetic field. Techniques are available to improve the performance of these systems in adverse magnetic and dynamic environments.