Precise Measurement of Magnetic Field for Geophysical, Space, and Security Applications

Measurement of small temporal and space variations of the magnetic field is required for many applications such as geophysics, space research, defense, industry, or security systems. In this paper, the focus is mainly paid on the vectorial sensors used in the unshielded environment. We proved that not only low noise, but also other parameters such as linearity and temperature stability are critical. High-temperature SQUID gradiometers are finding applications in the airborne scanning system as the magnetic field variations to be detected are small and the instruments cost is not prohibitive. Despite advances in the atomic magnetometers and small tunneling magnetoresistors, fluxgate sensors are usually the best solution for many applications. That is the reason why our research is focused on the development of fluxgate magnetometer. In the article many different applications of these sensors, involving for example mapping of the magnetic field using unmanned aerial vehicle (UAV), visualization of the magnetic field around the small UAV, spectrogram images created for the diagnostics of a ventilation system are presented. And based on the knowledge obtained during the research and application of magnetic sensors, the magnetometer application as a part of the developed security system is presented.