Analysis of topside sounder records

A large number of features can be seen on the ionograms obtained by the Canadian topside sounder satellite. The most useful feature for the calculation of electron density profile is the extraordinary trace; however, to achieve accurate results, the effect of the geomagnetic field must be carefully considered in the data reduction process. The method of analysis we selected assumes that small sections of the profile can be approximated by exponential laminations. This method requires fewer points than other first-order lamination techniques to achieve a given accuracy. It is usually assumed in the analysis that the received echoes correspond to vertical propagation. This assumption is not always valid, and it can in some cases lead to large errors. The sounder also excites the medium in the immediate vicinity of the satellite, giving rise to various plasma resonances. A graph is given which summarizes the local effects that are seen on the ionograms. This graph can be used for a rapid identification of these resonances.