Publications of H. Kopka

Basu, S.; Basu, S.; Stubbe, P.; Kopka, H.; Waarama, J.: Daytime scintillations induced by high-power HF waves at Tromsø, Norway. Journal Geophysical Research 92, pp. 11149 - 11157 (1987)

Kohl, H.; Kopka, H.; La Hoz, C.; Stubbe, P.: Propagation of artificially excited Langmuir waves in the ionosphere. Radio Science 22, pp. 655 - 661 (1987)

Rietveld, M. T.; Mauelshagen, H.-P.; Stubbe, P.; Kopka, H.; Nielsen, E.: The characteristics of ionospheric heating-produced ELF/VLF waves over 32 hours. Journal Geophysical Research 92, p. 8707 (1987)

Barr, R.; Stubbe, P.; Rietveld, M. T.; Kopka, H.: ELF and VLF signals radiated by the ``Polar Electrojet Antenna'': Experimental results. Journal Geophysical Research 91, pp. 4451 - 4459 (1986)

Barr, R.; Stubbe, P.; Rietveld, M. T.; Kopka, H.: ELF and VLF signals radiated by the "Polar Electrojet Antenna": experimental results. Journal Geophysical Research 91, pp. 4451 - 4459 (1986)

Hanuise, C.; Hedberg, A.; Oksman, J.; Nielsen, E.; Stubbe, P.; Kopka, H.: Comparison between the ionospheric plasma drift and the motion of artificially induced irregularities as observed by HF backscatter radars. Annales Geophysicae 4, p. 49 (1986)

Hedberg, Å.; Derblom, H.; Hamberg, G.; Thidé, B.; Kopka, H.; Stubbe, P.: Measurements of HF backscatter cross section for striations created by ionospheric heating at different power levels. Radio Science 21, pp. 117 - 125 (1986)

Hoeg, P.; Nielsen, E.; Stubbe, P.; Kopka, H.: Heater-induced 1-meter irregularities. Journal Geophysical Research 91, p. 11309 (1986)

Jones, T. B.; Robinson, T. R.; Stubbe, P.; Kopka, H.: EISCAT observations of the heated ionosphere. Journal of Atmospheric and Terrestrial Physics 48, pp. 1027 - 1035 (1986)

Rietveld, M. T.; Kopka, H.; Stubbe, P.: D-region characteristics deduced from pulsed ionospheric heating under auroral electrojet conditions. Journal of Atmospheric and Terrestrial Physics 48, pp. 311 - 326 (1986)

Barr, R.; Rietveld, M. T.; Kopka, H.; Stubbe, P.; Nielsen, E.: Extra-low frequency radiation from the polar electrojet antenna. Nature 317, p. 6033 (1985)

Barr, R.; Rietveld, M. T.; Kopka, H.; Stubbe, P.; Nielsen, E.: ELF radiation from the polar electrojet antenna. Nature 317, pp. 155 - 157 (1985)

Barr, R.; Rietveld, M. T.; Stubbe, P.; Kopka, H.: The diffraction of VLF radio waves by a patch of ionosphere illuminated by a powerful HF transmitter. Journal Geophysical Research 90, pp. 2861 - 2875 (1985)

Djuth, F. T.; Rost, R. J.; Noble, S. T.; Gordon, W. E.; Stubbe, P.; Kopka, H.; Nielsen, E.; Bostrom, R.; Derblom, H.; Hedberg, A. et al.; Thide, B.: Observations of E-region irregularities generated at auroral latitudes by a higher-power radio wave. Journal Geophysical Research 90, p. 12293 (1985)

Holt, O.; Brekke, A.; Hansen, T.; Kopka, H.; Stubbe, P.: HF modification of the auroral D-region detected by a partial reflection experiment. Journal of Atmospheric and Terrestrial Physics 47, pp. 537 - 545 (1985)

Holt, O.; Brekke, A.; Hansen, T.; Kopka, H.; Stubbe, P.: HF modification of the auroral d-region detected by a partial reflection experiment. Journal of Atmospheric and Terrestrial Physics 47, pp. 537 - 545 (1985)

Stubbe, P.; Kopka, H.; Rietveld, M. T.; Frey, A.; Hoeg, P.; Kohl, H.; Nielsen, E.; Rose, G.; La Hoz, C.; Barr, R. et al.; Derblan, H.; Hedberg, Å.; Thide, B.; Jones, T. B.; Robinson, T.; Brekke, A.; Hansen, T.; Holt, H.: Ionospheric modification experiment with the Tromsø heating facility. Journal of Atmospheric and Terrestrial Physics 47, p. 1151 (1985)

Stubbe, P.; Kopka, H.; Rietveld, M. T.; Frey, A.; HØeg, P.; Kohl, H.; Nielsen, E.; Rose, G.; La Hoz, C.; Barr, R. et al.; Derblom, H.; Hedeberg, Å.; Thidé, B.; Jones, T. B.; Robinson, T.; Brekke, A.; Hansen, T.; Holt, O.: Ionospheric modification experiments with the tromsØ heating facility. Journal of Atmospheric and Terrestrial Physics 12, pp. 1151 - 1163 (1985)

Barr, R.; Rietveld, M. T.; Kopka, H.; Stubbe, P.: Effect of a heated patch of auroral ionosphere on VLF-radio wave propagation. Nature 309, pp. 534 - 536 (1984)

Frey, A.; Stubbe, P.; Kopka, H.: First experimental evidence of HF produced electron density irregularities in the polar ionosphere, diagnosed by UHF radio star scintillations. Geophysical Research Letters 11, pp. 523 - 526 (1984)