Improved Magnetic Anomaly Navigation Accuracy through Cooperative Navigation

Abstract

Recent successful flight tests have demonstrated magnetic anomaly navigation as a promising GPS-alternative navigation technique. Magnetic field measurements alone have a small sensor aperture requiring a magnetic navigation system to collect several magnetic field measurements over time in order to navigate. In this paper, the authors propose a technique to improve the magnetic field sensor aperture—the use of shared magnetic field data in a cooperative navigation system with known relative positioning. A detailed simulation framework is implemented which explores the benefits of cooperative navigation using magnetic anomaly fields. The Cramer-Rao Lower Bound for cooperative magnetic anomaly navigation is presented and used to validate the simulation framework. A thorough set of trade-space studies are performed which predict cooperative navigation performance with respect to number or vehicles, altitude, velocity, and IMU quality. Trade-space results indicate that a simple cooperative navigation framework can greatly increase performance of the already promising technique of magnetic anomaly field navigation.