Auroral spectral estimation with wide-band color mosaic CCDs

Color mosaic CCDs use a matrix of different wide-band micro-filters in order to produce images with several (often three) color channels. These devices are increasingly employed in auroral studies to provide time sequences of two dimensional luminosity maps, but the color information is typically only used for qualitative analysis. In this study we use Backus–Gilbert linear inversion techniques to obtain quantitative measures of effective spectral resolution for multi-channel color mosaic CCDs. These techniques also allow us to explore the possibility of further improvements by modifying or combining multiple detectors. We consider two spectrally calibrated commercial color CCDs (Sony ICX285AQ and ICX429AKL) in order to determine effective wavelength resolution of each device individually, together, and with additional filters. From these results we develop methods to enhance the utility of existing data sets, and propose ways to improve the next generation of low-cost color auroral imaging systems.