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| Titel |
Auroral spectral estimation with wide-band color mosaic CCDs |
| VerfasserIn |
B. J. Jackel, C. Unick, M. T. Syrjäsuo, N. Partamies, J. A. Wild, E. E. Woodfield, I. McWhirter, E. Kendall, E. Spanswick |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2193-0856
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Instrumentation, Methods and Data Systems ; 3, no. 1 ; Nr. 3, no. 1 (2014-06-11), S.71-94 |
| Datensatznummer |
250115214
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| Publikation (Nr.) |
 copernicus.org/gi-3-71-2014.pdf |
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| Zusammenfassung |
Optical aurora can be structured over a wide range of spatial and temporal
scales with spectral features that depend on the energy of precipitating
particles. Scientific studies typically combine data from multiple
instruments that are individually optimized for spatial, spectral, or
temporal resolution. One recent addition combines all-sky optics with color
mosaic CCD (charge-coupled device) detectors that use a matrix of different wide-band micro-filters
to produce an image with several (often three) color channels. These devices
provide sequences of two dimensional multispectral luminosity with
simultaneous exposure of all color channels allowing interchannel comparison
even during periods with rapidly varying aurora. At present color auroral
image data are primarily used for qualitative analysis. In this study a
quantitative approach based on Backus–Gilbert linear inversion was used to
better understand the effective spectral resolution of existing and proposed
instruments.
Two spectrally calibrated commercial detectors (Sony ICX285AQ and ICX429AKL)
with very different color mosaics (RGB (red, green, blue) vs. CYGM (cyan, yellow, green, magenta)) were found to have very
similar spectral resolution: three channels with FWHM (full-width half-maximum) ≈100 nm; a
NIR (near infrared)
blocking filter is important for stabilizing inversion of both three-channel
configurations. Operating the ICX429AKL in a noninterlaced mode would
improve spectral resolution and provide an additional near infrared channel.
Transformations from arbitrary device channels to RGB are easily obtained
through inversion. Simultaneous imaging of multiple auroral emissions may be
achieved using a single-color camera with a triple-pass filter. Combinations
of multiple cameras with simple filters should provide ~50 nm
resolution across most of the visible spectrum. Performance of other
instrument designs could be explored and compared using the same quantitative
framework. |
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