Publication Date:
2019-09-01
Description:
Remote detection of geomagnetic fields in the mesosphere would provide a powerful tool for mapping and interpreting Earth's lithospheric magnetic fields, monitoring magnetic disturbances in conjunction with the aurora, and making long-term measurements of ionospheric currents at polar regions. Based on gated photon counting and direct frequency sweep, a remote magnetometry scheme with precession of mesospheric sodium was demonstrated. The technique of gated photon counting has an advantage in background light suppression and has the potential to achieve altitude-resolved magnetic field measurements with an optimized laser source. An intensity-modulated laser beam was utilized to optically pump sodium atoms in the mesopause, and a ground-based telescope collects fluorescent echoes to infer the magnetic field. The experiment was carried out at Lijiang observatory where we validated this technique and measured the geomagnetic field with a sensitivity of 849 nT/Hz1/2, which can be improved through further optimization.
Print ISSN:
2169-9380
Electronic ISSN:
2169-9402
Topics:
Geosciences
,
Physics
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