General expression of the frequencies of the oblique echoes at the plasma resonance

The frequencies of oblique echoes received by topside sounders at the plasma resonance are calculated without geometrical restrictions on the respective orientations of the static magnetic field, the gradient of electron density, and the satellite velocity. This work uses the WKB technique introduced by Fejer and Yu and is therefore an extension of these authors’ study. Such an extension should facilitate the interpretation of satellite data.