Evaluation of Simultaneous Localization and Calibration of a Train Mounted Magnetometer

Train localization is a key technology for automating railway traffic and using the railway infrastructure efficiently. Localization must be available independent from the environment and must provide a high accuracy and reliability. A single localization solution most likely will not be able to fulfill this requirement. GNSS for example will not be available in tunnels. In this paper, we therefore investigate an alternative localization method based on position-dependent distortions of the Earth magnetic field. The advantage of this approach is that it is also available in GNSS-denied areas. If GNSS is available, it can be seen as a low-cost method to obtain redundant position information. The work presented here is an evaluation of the algorithm proposed in our prior work [1], in which we showed how an uncalibrated magnetometer can be used to simultaneously estimate the position of a model train and the magnetometer calibration parameters. The evaluation presented in this paper applies the simultaneous localization and calibration algorithm to data measured with two different trains driving on a rural track network in Germany. The evaluation shows that magnetic field based localization using only an uncalibrated magnetometer is also possible in real railway environments