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First Performance Results of a New Geocoronal Balmer-Alpha Field-Widened Spatial Heterodyne Spectrometer
American Geophysical Union Annual Fall Meeting (2015)
  • D. Gardner, University of Wisconsin - Madison
  • Edwin J. Mierkiewicz, Embry-Riddle Aeronautical University
  • F. L. Roesler, University of Wisconsin - Madison
  • J. Harlander, St. Cloud State University
  • K. Jaehnig, University of Wisconsin - Madison
  • S. Nossal, University of Wisconsin - Madison
  • L. M. Haffner, University of Wisconsin - Madison
During 2013, a new, high resolution field-widened spatial heterodyne spectrometer (FW-SHS) uniquely designed to observe geocoronal Balmer-alpha emission ([Ha], 6563A) was installed at Pine Bluff Observatory (PBO) near Madison Wisconsin. FW-SHS observations were compared with an already well-characterized dual-etalon Fabry Perot Interferometer (FPI) optimized for [Ha], also at PBO. The FW-SHS is a robust new Fourier-transform instrument that combines a large throughput advantage with high spectral resolution and a relatively long spectral baseline (~10x that of the FPI) in a compact, versatile instrument with no moving parts. Coincident [Ha] observations by FW-SHS and FPI were obtained over similar integration times, resolving power (~80,000 at [Ha]) and field-of-view (1.8 and 1.4 degrees, respectively). This paper describes the FW-SHS first light performance and [Ha] observational results collected from observing nights across 2013 and 2014. Initial FW-SHS observations of Balmer-alpha intensity and temperature (doppler width) vs. viewing geometry (shadow altitude) show excellent relative agreement with the geocoronal observations previously obtained at PBO by FPI. The FW-SHS is capable of determining geocoronal Balmer-alpha doppler shifts on the order of 100 m/s across a 640km/s [Ha] spectral bandpass,with a temporal resolution on the order of minutes. These characteristics make the FW-SHS well suited for spectroscopic studies of relatively faint, diffuse-source geocoronal Balmer-alpha emission from Earths upper atmosphere (~2-14R) and the interstellar medium in our Galaxy. Current and future observations expand long-term geocoronal hydrogen observation data sets already spanning two solar maximums.
  • Middle atmosphere,
  • thermosphere,
  • topside ionosphere,
  • atmospheres
Publication Date
Publisher Statement
(Poster) Abstract SA-43A-2358
Citation Information
D. Gardner, Edwin J. Mierkiewicz, F. L. Roesler, J. Harlander, et al.. "First Performance Results of a New Geocoronal Balmer-Alpha Field-Widened Spatial Heterodyne Spectrometer" American Geophysical Union Annual Fall Meeting (2015)
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