MIRACLE data analysis tools

9) Inversion method for all-sky camera images :

- Short description of the method:

The inversion method, ASCinv, is used to estimate the total electron energy flux based on the brightness of the aurora. It can be used for a single image from a single station, or for multiple images from multiple stations. To give meaningful energy flux values, the method requires that the camera data are calibrated. In addition to the intensity and position calibration information, the inversion uses model ionosphere height profiles of volume emission rates for the wavelengths 557.7nm, 630.0nm and 427.8nm [Rees 1963, 1989].

The blue auroral emission results in the most accurate energy flux, with a relative error only about 10% as compared to the in situ satellite data [Partamies et al. 2004].

- Example plot:

Two-dimensional map of inverted electron energy flux. This inversion run used the combination of green (557.7 nm) and blue (427.8 nm) images from Muonio station. The map is in geographical coordinates and the energy flux is colour-coded. The bright spot in the lower part of the map is the Moon. The blue labels mark the DMSP satellite overpass.

For further information, see the original publication by Pekka Janhunen.