Particle-wave and wave-wave interactions generated during T.B.F. transmission from Kafjord, Norway

Interactions in the magnetosphere between man-made VLF waves and electrons can produce either an enhancement of the wave or the generation of waves at a different frequency. Furthermore natural emissions can be frequency shifted or modified by a nearby transmitter signal. Injections of VLF waves into the magnetosphere was initiated using a 15 km power line (antenna) tuned at the transmitted frequency. A 1 KW transmitter was used to drive the antenna with a maximum current of 8 amperes. Transmissions were conducted when the SCATHA and GOES II satellites were near the magnetic meridian of the transmitter. Transmitted signals were either keyed fixed frequency or continuous waves swept in frequency. Signals correlated with the transmissions were detected by the satellite receivers on several dates. With the first types of transmission, signals similar to power line harmonic radiation were recorded. Artificially stimulated emissions, chorus elements, and magnetospheric induced quiet band are also likely to have been triggered. Both types of transmissions triggered or enhanced hiss at a constant frequency during fixed frequency transmissions or at a variable frequency during a swept frequency transmission.