MI-FPD: Magnetic Information of Free Precession Signal Data Measurement Method for Bell–Bloom Magnetometer

The free precession style Bell–Bloom atomic magnetometer is widely used in geophysical exploration, earthquake monitoring, and natural disaster monitoring to obtain magnetic field information by measuring the Larmor frequency of the free precession signal. However, the free precession signal complexity makes it challenging to accurately acquire the Larmor frequency using conventional frequency measurement methods, limiting its applicability. This study proposes a magnetic information of free precession signal data (MI-FPD) algorithm for measuring the Larmor frequency of the free precession signal in the Bell–Bloom atomic magnetometer. The MI-FPD algorithm accurately determines the Larmor precession frequency based on free precession signal data, providing precise magnetic field information. The algorithm outperforms established algorithms regarding convergence efficiency, accuracy, and noise resistance, with an optimal determination coefficient
$R^{2}$
of 0.99984, an optimal range of less than 1.04 nT, and an optimal root mean square error (RMSE) of 189 pT. These results demonstrate the effectiveness of the proposed algorithm in accurately obtaining magnetic field information in the free precession style Bell–Bloom atomic magnetometer. This capability enables widespread application of the free precession style Bell–Bloom atomic magnetometer in geomagnetic monitoring and disaster early warning within the geoscience domain. The shareable data are available at
https://github.com/baicaidezhenshi/MI-FPD-DATA.git
.