Greifswald 2009 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 7: Poster Session Extraterrestrics
EP 7.8: Poster
Dienstag, 31. März 2009, 17:30–19:00, Foyer der Zahnklinik
High-frequency magnetospheric sounding at EISCAT: some trials and their implications — Andrew Senior1, Farideh Honary1, •Michael Rietveld2, Peter Chapman1, and Mike Kosch1 — 1Dept. of Communication Systems, Lancaster University, LA1 4WA, U. K. — 2EISCAT Scientific Association, N-9027 Ramfjordbotn, Norway
The results of some recent experiments employing the EISCAT HF heating facility at Ramfjordmoen, near Tromsø, Norway as a HF radar transmitter are described. The motivation for the experiments was the detection of conjugate echoes caused by geomagnetic field-aligned ducting of the HF wave in the magnetosphere and reflection from the magnetically-conjugate ionosphere. No such echoes were detected during the experiments, which is probably to be expected from consideration of the plasma density gradients required to sustain guidance of the waves at the low HF frequencies involved. However, echoes were obtained at ranges which could be consistent with backscattering from ionospheric irregularities in the equatorial and southern auroral regions; this is similar to spread-Doppler clutter observed by large over-the-horizon radar (OTHR) systems. The technique and results are discussed with a view towards future attempts to sound the lower magnetosphere using high-power HF transmitters. If the coherent echoes associated with aurora observed using the UHF and VHF EISCAT radars also exist at HF, then HF sounding may be a powerful new tool for studies of the aurora.