1. Laser remote magnetometry using mesospheric sodium
- Author
-
Kane, Thomas J., Hillman, Paul D., Denman, Craig A., Hart, Michael, Scott, R. Phillip, Purucker, Michael E., Potashnik, Stephen J., Kane, Thomas J., Hillman, Paul D., Denman, Craig A., Hart, Michael, Scott, R. Phillip, Purucker, Michael E., and Potashnik, Stephen J.
- Abstract
We have demonstrated a remote magnetometer based on sodium atoms in the Earth's mesosphere, at a 106-kilometer distance from our instrument. A 1.33-watt laser illuminated the atoms, and the magnetic field was inferred from back-scattered light collected by a telescope with a 1.55-meter-diameter aperture. The measurement sensitivity was 162 nT/$\sqrt{Hz}$. The value of magnetic field inferred from our measurement is consistent with an estimate based on the Earth's known field shape to within a fraction of a percent. Projected improvements in optics could lead to sensitivity of 20 nT/$\sqrt{Hz}$, and the use of advanced lasers or a large telescope could approach 1-nT/$\sqrt{Hz}$ sensitivity. All experimental and theoretical sensitivity values are based on a 60$^\circ$ angle between the laser beam axis and the magnetic field vector; at the optimal 90$^\circ$ angle sensitivity would be improved by about a factor of two., Comment: 15 pages, 15 figures, 4 tables
- Published
- 2016