@article{e8201482ed874f0cafe0849efb4bff44,
title = "Laser Remote Magnetometry Using Mesospheric Sodium",
abstract = "We have demonstrated a remote magnetometer based on sodium atoms in the Earth's mesosphere, at a 106-km distance from our instrument. A 1.33-watt laser illuminated the atoms, and the magnetic field was inferred from backscattered light collected by a telescope with a 1.55-m-diameter aperture. We theoretically predict a shot noise limited measurement sensitivity of 19 nT/√Hz. The measured sensitivity was 162 nT/√Hz due to a smaller returned intensity and smaller resonance strength than expected. The value of magnetic field inferred from our measurement is consistent with several models of the Earth's field shape to within a fraction of a percent. Projected improvements in optics, plus the use of advanced lasers or a large telescope, could result in 1-nT/√Hz sensitivity.",
keywords = "Kuiper telescope, atomic magnetometry, laser guide star, mesosphere, sodium",
author = "Kane, {Thomas J.} and Hillman, {Paul D.} and Denman, {Craig A.} and Michael Hart and {Phillip Scott}, R. and Purucker, {Michael E.} and Potashnik, {S. J.}",
note = "Funding Information: The results presented in this paper rely on data collected at the Tucson Magnetic Observatory. We thank the U.S. Geological Survey for supporting its operation and INTERMAGNET for promoting high standards of magnetic observatory practice (www. intermagnet.org), and the National Geomagnetism Program (observatory location Tucson, AZ): http://geomag. usgs.gov/monitoring/observatories/ tucson/, http://geomag.usgs.gov/map/ #realtime, and http://geomag.usgs.gov/ plots/ We would also like to acknowledge the University of Arizona, Steward Observatory, for the use of the Kuiper Telescope and the 589-nm FASOR coherent light source. Special thanks go to Jim Grantham and Steve Bland of the Stewart Observatory Mount Operations Team for making some last minute unscheduled telescope configuration changes, and finally Duncan Reed for weathering several cold nights airplane spotting. This material is based upon work supported by the U.S. Navy, Office of Naval Research - Code 321 under contract N00014-11-C-0314 and N00014-14-C- 0110. The Final Report for the earlier contract provided estimates for both the sensitivity of the laser-based remote measurement under various conditions, and for the correlation that would be observed between high-altitude data and surface data. The authors feel the most pertinent figures in this paper are Figures 9 and 12. The original raw data for these figures are available for download in two Excel spreadsheets at https://wp.optics.arizona.edu/ adaptiveoptics/wp-content/uploads/ sites/68/2018/03/figures.zip. Data for other figures discussed in the analysis can be derived from these data. We also thank the two reviewers for thoroughly reading our paper and making a few suggested changes to help clarify some fine details. Funding Information: The results presented in this paper rely on data collected at the Tucson Magnetic Observatory. We thank the U.S. Geological Survey for supporting its operation and INTERMAGNET for promoting high standards of magnetic observatory practice (www.intermagnet.org), and the National Geomagnetism Program (observatory location Tucson, AZ): http://geomag.usgs.gov/monitoring/observatories/tucson/, http://geomag.usgs.gov/map/#realtime, and http://geomag.usgs.gov/plots/ We would also like to acknowledge the University of Arizona, Steward Observatory, for the use of the Kuiper Telescope and the 589-nm FASOR coherent light source. Special thanks go to Jim Grantham and Steve Bland of the Stewart Observatory Mount Operations Team for making some last minute unscheduled telescope configuration changes, and finally Duncan Reed for weathering several cold nights airplane spotting. This material is based upon work supported by the U.S. Navy, Office of Naval Research - Code 321 under contract N00014-11-C-0314 and N00014-14-C-0110. The Final Report for the earlier contract provided estimates for both the sensitivity of the laser-based remote measurement under various conditions, and for the correlation that would be observed between high-altitude data and surface data. The authors feel the most pertinent figures in this paper are Figures?9 and 12. The original raw data for these figures are available for download in two Excel spreadsheets at https://wp.optics.arizona.edu/adaptiveoptics/wp-content/uploads/sites/68/2018/03/figures.zip. Data for other figures discussed in the analysis can be derived from these data. We also thank the two reviewers for thoroughly reading our paper and making a few suggested changes to help clarify some fine details. Publisher Copyright: {\textcopyright}2018. American Geophysical Union. All Rights Reserved.",
year = "2018",
month = aug,
doi = "10.1029/2018JA025178",
language = "English (US)",
volume = "123",
pages = "6171--6188",
journal = "Journal of Geophysical Research: Space Physics",
issn = "2169-9380",
number = "8",
}