Blar i tittel Artikler, rapporter og annet (EISCAT)

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    • Probing of medium-scale traveling ionospheric disturbances using HF-induced scatter targets 

      Blagoveshchenskaya, N. F.; Rietveld, Michael T.; Borisova, T. D.; Kornienko, V. A.; Moskvin, I. V.; Frolov, V. L.; Uryadov, V. P.; Kagan, L. M.; Yampolski, Yu. M.; Galushko, V. L.; Koloskov, A. V.; Kasheev, S. B.; Zalizovski, A. V.; Vertogradov, G. G.; Vertogradov, V. G.; Kelley, M. C. (Journal article; Tidsskriftartikkel; Peer reviewed, 2006-09-20)
      Experimental results from the Tromsø and Sura heating experiments at high and mid-latitudes are examined. It is shown that the combination of HF-induced target and bi-static HF Doppler radio scatter observations is a profitable method for probing medium-scale traveling ionospheric disturbances (TIDs) at high and mid-latitudes. HF ionospheric modification experiments provide a way of producing ...

    • The relationship between small-scale and large-scale ionospheric electron density irregularities generated by powerful HF electromagnetic waves at high latitudes 

      Rietveld, Michael T.; Tereshcenko, E.D.; Khudukon, B.Z.; Brekke, Asgeir; Isham, B.; Hagfors, T. (Journal article; Tidsskriftartikkel; Peer reviewed, 2006-11-21)
      Satellite radio beacons were used in June 2001 to probe the ionosphere modified by a radio beam produced by the EISCAT high-power, high-frequency (HF) transmitter located near Tromsø (Norway). Amplitude scintillations and variations of the phase of 150- and 400-MHz signals from Russian navigational satellites passing over the modified region were observed at three receiver sites. In several papers ...

    • Statistical signature of active D-region HF heating in IRIS riometer data from 1994–2004 

      Kero, A.; Rietveld, Michael T.; Enell, C.-F.; Ulich, Th.; Turunen, E.; Honary, F. H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2007-03-08)
      In this paper we study the effect of artificial HF heating on cosmic radio noise absorption in the D-region ionosphere. The effect has earlier been studied theoretically in idealised cases and without experimental verification. Here we present a 3-dimensional modelling of the effect, taking into account the directivity patterns of the vertical beam of the EISCAT Heater at Tromsø, Norway, and ...

    • Stimulated Brillouin scattering during electron gyro-harmonic heating at EISCAT 

      Fu, Haiyang; Scales, Wayne A.; Bernhardt, Paul A.; Briczinski, Stan J.; Kosch, Michael J.; Senior, Andrew; Rietveld, Michael T; Yeoman, Timothy Kenneth; Ruohoniemi, J. Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-11)
      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 narrowband SEE in the form of stimulated Brillouin scatter (SBS) and stimulated ion Bernstein ...

    • Survey of conditions for artificial aurora experiments at EISCAT Tromsø using dynasonde data 

      Tsuda, T. T.; Rietveld, Michael T; Kosch, Michael J.; Oyama, S; Hosokawa, K.; Nozawa, Satonori; Kawabata, T; Mizuno, A; Ogawa, Y (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-14)
      We report a brief survey on conditions for artificial aurora optical experiments in F region heating with O-mode at the EISCAT Tromsø site using dynasonde data from 2000 to 2017. The results obtained in our survey indicate the following: The possible conditions for conducting artificial aurora experiments are concentrated in twilight hours in both evening and morning, compared with late-night hours; ...

    • Survey of conditions for artificial aurora experiments by the second electron gyro-harmonic at EISCAT Troms? using dynasonde data 

      Tsuda, T. T.; Rietveld, Michael T; Kosch, M.J; Oyama, S; Ogawa, Y; Hosokawa, K.; Nozawa, S; Kawabata, T; Mizuno, A (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-06)
      We report a brief survey of matching conditions for artificial aurora optical experiments utilizing the second electron gyro-harmonic (2.7-MHz frequency) in F region heating with O-mode at the EISCAT Tromsø site using dynasonde data from 2000 to 2017. Our survey indicates the following: The possible conditions for successful artificial aurora experiments are concentrated on twilight hours in both ...

    • Systematic variation in observing altitude of enhanced ion line by the pump near fifth gyroharmonic 

      Wu, Jun; Rietveld, Michael T; Häggström, Ingemar; Zhao, H.; Xu, T; Xu, Z (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-20)
      The observation of ultra high frequency radar during an ionospheric experiment carrying out at the European Incoherent Scatter Scientific Association, demonstrates a systematic variation in the altitude of the pump enhanced ion line, which is quite remarkably dependent on the pump frequency, that is, when the pump frequency sweeps above the fifth gyroharmonic, the altitude of the enhanced ion line ...