The global distribution of natural and man‐made ionospheric electric fields at 200 kHz and 540 kHz as observed by Ogo 6

摘要: Our experiment on the polar-orbiting Ogo 6 spacecraft (perigee 400 km, apogee 1100 km) yielded real time analog data in several broad band channels and essentially continuous tape-recorded from two narrow (200 Hz) receivers operating at 200 540 kHz. The results show that worldwide distribution of signals kHz falls into a number different categories: (1) naturally generated (auroral) hiss polar latitudes with typical 200-kHz intensities around 0.1 µV m−1 Hz−1/2, maximum up to generally lower kHz; (2) nighttime mid-latitude enhancements few microvolts per meter, which probably result either superposition 200- 540-kHz stations or interference intense much higher frequencies; (3) well-defined signal peaks associated individual ground (these upward-propagating appear be guided along earth's magnetic field may reach an intensity hundred meter); (4) striking conjugate region low-latitude station (Achkhabad), suggesting propagation whistler mode opposite hemisphere; (5) occasional equator, are present unexplained.