Geographic True Navigation Based on Real-Time Measurements of Geomagnetic Fields

Inspired by animals’ long-distance migration behaviors, we proposed a novel and reliable long-distance true navigation method based on the measurement of geomagnetic fields. By establishing a 2-D gradient approaching a coordinate plane with geomagnetic intensity and inclination, long-distance true navigation can be achieved from any starting spot in this area. Without other calibration and auxiliary information, this navigation method is highly independent, which can be used in electromagnetic shielding circumstances, such as a deep ocean. The geomagnetic intensity and inclination gradients are estimated with real-time measurement of the geomagnetic field along the navigation trajectory. With estimated local gradients, a 2-D gradient approaching algorithm can be applied to predict the heading direction, and the agent can press on toward the destination step by step. Theoretical analysis and Monte Carlo simulations verified the feasibility and practicality of this method, proving its robustness in the presence of interference and different measurement errors. It can be a promising candidate in the design of navigation systems used in autonomous underwater vehicles (AUVs) or platforms.