The quantitative analysis of UVI images is done in several steps. The goal is to obtan maps of auroral brightness, maps of auroral electron precipitation parameters (mean energy and energy flux), and maps of Hall and Petersen conductances.
The image pixel locations are determined in geographic and geomagnetic coordinates, assuming an emission altitude of 120 km.
The calibration and flatfielding is applied to the image.
Using the geographic coordinates, the solar EUV (photoelectrons) contribution to the image pixel brightness is determined and subtracted from the image.
The image pixels are binned into superpixels which are typically 1° in magnetic latitude and 0.5 hours in magnetic local time. Binning is flexible depending on the objective of the analysis and can be as small as 0.25° by 0.1 hours or as large as 2° by 1 hour.
Ratios of the brightness in LBH-long and LBH-short filters of these superpixels are used to determine the mean energy. The brightness of LBH-long is used to determine the energy flux.
Mean energy and energy flux are used to determine the ionospheric conductances.
The maps of the mean energy, energy flux, and conductances are used as input to the assimilative mapping of ionospheric electrodynamics (AMIE). Integrating the energy flux over all latitudes and longitudes gives the hemispheric power, or the fraction of the hemispheric power in the field of view of te instrument. Examples and applications of this analysis are published in various articles. Here is list of events that have been analyzed.
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