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A Synthesis of Star Calibration Techniques for Ground-Based Narrowband Electron-Multiplying Charge-Coupled Device Imagers Used in Auroral PhotometryA technique is presented for the periodic and systematic calibration of ground-based optical imagers. It is important to have a common system of units (Rayleighs or photon flux) for cross comparison as well as self-comparison over time. With the advancement in technology, the sensitivity of these imagers has improved so that stars can be used for more precise calibration. Background subtraction, flat fielding, star mapping, and other common techniques are combined in deriving a calibration technique appropriate for a variety of ground-based imager installations. Spectral (4278, 5577, and 8446 A ) ground-based imager data with multiple fields of view (19, 47, and 180 deg) are processed and calibrated using the techniques developed. The calibration techniques applied result in intensity measurements in agreement between different imagers using identical spectral filtering, and the intensity at each wavelength observed is within the expected range of auroral measurements. The application of these star calibration techniques, which convert raw imager counts into units of photon flux, makes it possible to do quantitative photometry. The computed photon fluxes, in units of Rayleighs, can be used for the absolute photometry between instruments or as input parameters for auroral electron transport models.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Grubbs, Guy II (Catholic Univ. of America Washington, DC, United States)
Michell, Robert (Maryland Univ. College Park, MD, United States)
Samara, Marilia (NASA Goddard Space Flight Center Greenbelt, MD United States)
Hampton, Don (Alaska Univ. Fairbanks, AK, United States)
Jahn, Jorg-Micha (Southwest Research Inst. San Antonio, TX, United States)
Date Acquired
March 31, 2017
Publication Date
June 21, 2016
Publication Information
Publication: Journal of Geophysical Research: Space Physics
Volume: 121
Issue: 6
ISSN: 2169-9402
Subject Category
Instrumentation and Photography
Report/Patent Number
Funding Number(s)
Distribution Limits