Atmospheric Magnetic Noise Measurements in Urban Areas

The theory of atmospheric magnetic noise is reviewed and we discuss how it impacts magnetoinductive communications systems. Magnetic noise measurements are then conducted to obtain quantitative values of the noise levels at both indoor and outdoor locations. The measurements, using an industrial-grade magnetometer, are compared with results from Comité Consultatif International des Radiocommunications (CCIR) measurements conducted using an electric antenna, and then converted via the E-H relationship in vacuum. Both measurements are in agreement other than in a small frequency range, whereas the CCIR electric measurements show pessimistic minimal values, possibly due to electrical interference.