This paper has the main purpose to give an introductory survey on the
various systems that exploit magnetic fields for positioning. Such
systems find applications in those scenarios, both indoors and outdoors,
where Global Navigation Satellite Systems (GNSS) are not available or
fail to provide information with the needed accuracy. While the main
idea of using electromagnetic fields to provide position information
dates back to the past century, new application–led research on this
topic has emerged in recent years. Results have expanded the application
range of Magnetic Positioning (MP) technologies and form now a domain of
knowledge that enables realization of positioning systems applicable to
indoor and outdoor environments.
The paper provides the main characteristics of different positioning
systems with focus on those solutions that are based on low–frequency
magnetic fields. Some background theory is presented and positioning
results from the literature are analyzed and compared.