Sources of stationary and low-frequency magnetic fields in inhabited areas

This document exposes some of the sources of stationary and low-frequency magnetic fields that can be found in inhabited areas. One of the strongest magnetic field that one can observe is the Earth's magnetic field with an average of 48 µT in Central Europe. However, living in the 21st century, it is one of the few magnetic fields originating from a natural source. Modern life involves innumerable artificial sources of (electromagnetic c fields, ranging from simple refrigerator magnets to wireless LAN. These " man-made " fields are often linked to electric currents respectively to electric fields and occur in a frequency domain from 0 Hz to several GHz [18]. We consider here magnetometers working at relatively low frequencies, that is to say less than 500 Hz. In addition, only magnetic fields greater than 3 · σ noise = 1.35 µT can be clearly distinguished from noise of the embedded magnetometers [20]