Application of stochastic inversion in auroral tomography

A software package originally developed for satellite radio tomography is briefly introduced and its use in two-dimensional auroral tomography is described. The method is based on stochastic inversion, i.e. finding the most probable values of the unknown volume emission rates once the optical measur...

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Bibliographic Details
Published in:Annales Geophysicae
Main Authors: T. Nygrén, M. Markkanen, M. Lehtinen, K. Kaila
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 1996
Subjects:
Q
Online Access:https://doi.org/10.1007/s00585-996-1124-1
https://doaj.org/article/8a71290a29ca4526901908b9cc32a0bb
Description
Summary:A software package originally developed for satellite radio tomography is briefly introduced and its use in two-dimensional auroral tomography is described. The method is based on stochastic inversion, i.e. finding the most probable values of the unknown volume emission rates once the optical measurements are made using either a scanning photometer or an auroral camera. A set of simulation results is shown for a different number and separations of optical instruments at ground level. It is observed that arcs with a thickness of a few kilometers and separated by a few tens of kilometers are easily reconstructed. The maximum values of the inversion results, however, are often weaker than in the model. The most obvious reason for this is the grid size, which cannot be much smaller than the arc thickness. The grid necessarily generates a spatial averaging effect broadening the arc cross-sections and reducing the peak values. Finally, results from TV-camera observations at Tromsø and Esrange are shown. Although these sites are separated by more than 200 km, arcs close to Tromsø have been successfully reconstructed.