Fig. 11From: Development of low-cost sky-scanning Fabry-Perot interferometers for airglow and auroral studiesExamples of 630.0-nm sky (a) and HeNe 632.8-nm laser (c) images and interferograms for each ((b) and (d)) showing the results of annular integration about the ring center for the 12 orders shown. The blue line is the Levenberg Marquardt non-linear least square model fit to the data points for each of the two orders shown in (b) and (d).Back to article page