Observations by DEMETER of Man‐Made MF Waves Escaping From the Ionosphere

DEMETER was a low altitude satellite on polar and circular orbit devoted to the study of ionospheric perturbations in relation with seismic activity. Its scientific payload waves plasma measurements also allows man-made waves. The aim this paper is check conditions apparition these MF range (300 kHz, 3 MHz). These normally propagate Earth-ionosphere waveguide, but it shown that they can escape above ionosphere when there decrease electron density. This meanly occurs at troughs are close inhabited areas, South Atlantic Anomaly magnetic activity high.