Magnetic Anomaly Navigation with a Lie-Group Error-State Kalman Filter

Magnetic anomaly navigation (MagNav) is a navigation method using the magnetic signature of the Earth’s crust as a position reference. It has recently gained interest within the navigation community. The signal’s global availability at any time without dependence on external transmitters makes it attractive for the development of more resilient airborne navigation systems. Increasing risk of global navigation satellite systems (GNSS) unavailability combined with technological advances in high-performing quantum magnetometers currently increases the interest in this method. Here we present a novel magnetic anomaly navigation algorithm based on an error-state Kalman filter on the SE<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>(3) Lie Group of extended poses. In state-of-the-art algorithms for aviation, the growing error of a position provided by an inertial system is corrected with a feedforward filter. In contrast, our algorithm is based on feedback corrections of the inertial system. We demonstrate the performance of our navigation algorithm on simulated data and show that it can successfully compensate the position drift of both tactical and navigation grade IMUs using magnetic anomaly maps with sufficient spatial variability. Our work paves the way towards more robust implementations of alternative aircraft navigation methods in case of GNSS-denial.