Review of Advantages and Disadvantages of Magnetometer Types and Measuring Techniques to be Used for GNSS-free PNT in the Maritime Environment

Reliable determination of position, navigation and timing (PNT) is essential for safe shipping traffic. PNT using the Earth's magnetic anomaly field, which is always globally available, is a promising alternative to satellite-based positioning which can be disturbed in case of conflicts. The aim of the review is to give an overview of the advantages and disadvantages of magnetometer technologies and data gathering methods with respect to positioning and their restrictions of the maritime environment such as specific setups, necessary accuracy and sensitivity as well as measurement frequency to obtain the high frequency components of the earth magnetic field.