MagSLAM: Aerial simultaneous localization and mapping using Earth's magnetic anomaly field

Abstract

Instances of spoofing and jamming of global navigation satellite systems (GNSSs) have emphasized the need for alternative navigation methods. Aerial navigation by magnetic map matching has been demonstrated as a viable GNSS‐alternative navigation technique. Flight test demonstrations have achieved accuracies of tens of meters over hour‐long flights, but these flights required accurate magnetic maps which are not always available. Magnetic map availability and resolution vary widely around the globe. Removing the dependency on prior survey maps extends the benefits of aerial magnetic navigation methods to small unmanned aerial systems (sUAS) at lower altitudes where magnetic maps are especially undersampled or unavailable. In this paper, a simultaneous localization and mapping (SLAM) algorithm known as FastSLAM was modified to use scalar magnetic measurements to constrain a drifting inertial navigation system (INS). The algorithm was then demonstrated on real magnetic navigation flight test data. Similar in performance to the map‐based approach, MagSLAM achieved tens of meters accuracy in a 100‐minute flight without the use of a prior magnetic map. Aerial SLAM using Earth's magnetic anomaly field provides a GNSS‐alternative navigation method that is globally persistent, impervious to jamming or spoofing, stealthy, and locally accurate to tens of meters without the need for a magnetic map.

Magnetic-field Based Odometry – An Optical Flow Inspired Approach

“…This corresponds to the noise level of the low-cost magnetometer RM3100 from PNI Sensor, US. 2 Using the simulated array measurements the pose change of the array was estimated using (3) and the root-mean-squareerrors (RMSE)…”

“…1. Hence, these fields constitute a viable and robust information source for localization in Global Navigation Satellite System (GNSS) denied environments, such as indoors or underwater [2], [3]. Indeed, recent research on magneticfield based simultaneous localization and mapping (SLAM) using low-cost magnetometers and inertial sensors has shown impressive results and opened up a potential path toward scalable and accurate pedestrian indoor localization [4], [5].…”

Kalman–Hatch dual‐filter integrating global navigation satellite system/inertial navigation system/on‐board diagnostics/altimeter for precise positioning in urban canyons

“…A magnetic compass can support heading information with good availability based on the direction of the Earth's magnetic field [14,15]. However, the field direction is easily distorted by the adjacent magnetic materials or iron structures.…”

Onboard and External Magnetic Bias Estimation for UAS through CDGNSS/Visual Cooperative Navigation

“…Recent references addressing magnetometer calibration, but dealing only with estimation of onboard disturbances, can be found in [ 8 , 9 ]. Other recent approaches also focus on the idea to exploit the variations of the external magnetic field also as a source of positioning information: in [ 10 ], a magnetic-based simultaneous location and mapping (SLAM) approach has been studied as an alternative to the usual GNSS-based navigation. Such work is mainly focused on the analysis of a magnetic-based navigation concept which does not rely on prior Earth magnetic anomaly field maps.…”