New stimulated electromagnetic emission experiment at EISCAT

摘要

Observations of secondary radiation, Stimulated Electromagnetic Emission (SEE), produced during ionospheric modification experiments using ground-based high-power high frequency HF radio waves are considered. The High Frequency Active Auroral Research Program (HAARP) facility is capable of generating Magnetized Stimulated Brillouin scatter MSBS and Stimulated Ion Bernstein scatter SIBS in the SEE spectrum. Narrowband SEE features have not been observed at EISCAT before. Narrowband MSBS spectrums are compared to such behavior previously observed at HAARP. Preliminary analyses of SEE data show observation of ion acoustic emission lines due to stimulated Brillouin scatter during the 2012 July EISCAT campaign. For varying heater antenna beam angles, the CUTLASS radar backscatter induced by HF radio pumping is suppressed near electron gyro-harmonics whereas electron temperature enhancement weakens measured by EISCAT/UHF radar.