Instruments:pfp

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Peach Mountain Fabry-Perot

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Acknowledgments

The Peach Mountain Fabry-Perot was built with funds from the College of Engineering of the University of Michigan, and is supported by funding from the National Science Foundation and the National Aeronautics and Space Administration.

Data Description

The Peach Mountain (also known as Stinchfield Woods) Fabry-Perot interferometer, operated by the Space Physics Research Laboratory, Department of Atmospheric, Oceanic and Space Sciences of the University of Michigan is located at latitude 42.40N and longitude 83.96W, and at an altitude of 955 ft.

Currently, the interferometer observes the line profile of the forbidden emission OI (5577 A) and OH (8920 A). The geophysical parameters obtained from the data reduction are the gas kinetic temperature of the emitting region from the natural width of the sky profile, the line of sight wind from the Doppler shift of the sky profile, and the surface brightness of the emission line. OI (5577 A) nightglow emission is generally believed to issue from the altitude range 85 to 300 km, with the major contribution originating from a narrow height interval roughly 10 to 15 km broad centered at 97 km. Similarly, the Meinel OH emission also issues from a broad altitudinal range though centered at a lower altitude. Thus, it is difficult to assign a unique altitude to each ground based OI (5577 A) and OH (8920 A) interferometer measurement. If no other information is available, we generally ascribe 97 km as the altitude of OI (5577 A) emission and 86 km for the OH emission.

Line of sight winds derived from the observed shift of the emission line from a zero reference position requires the determination of a zero wind. The reference zero wind is taken to be the average of an entire nights vertical wind data. Generally, the four cardinal directions are also sampled as well as the vertical. There is no exclusion of any data in the CEDAR Data Base, so cloudy night fits are also included. The cloud cover (code 440) measured by the Detroit Metro airport meteorological station is given in octas of the sky covered. Values range from 0 (clear) to 9 (overcast). In the summary plots, wind measurements were not plotted unless the cloud cover was 0-3. Temperatures and relative emission measurements were not plotted unless the cloud cover was 0-6.

References for the instrument and data processing procedures

Killeen et al., Appl. Opt. 23, 612 (1984)
McCormac et al., Planet. Space Sci. 35, 1255 (1987)
Meriwether et al., Opt. Eng. 22, 128 (1983)
Niciejewski et al., SPIE Proceedings, 1745, 165 (1992)

Summary Plots for Peach Mountain Fabry-Perot in OH (892.0nm, ~86 km) and Green Line (557.7 nm, ~97 km)

Summary plots of the 4 cardinal directions of the horizontal winds, the vertical winds, relative emission and temperature. The relative emission and relative neutral temperature show values for the vertical look direction from both filters. In the summary plots, wind measurements were not plotted unless the cloud cover was 0-3. Temperatures and relative emission measurements were not plotted unless the cloud cover was 0-6.


-Revised 26 March 2007 by Barbara Emery