ANGEO Annales Geophysicae ANGEO 1432-0576 Copernicus GmbH Göttingen, Germany 10.5194/angeo-20-1023-2002 Determining characteristics of HF communications links using SuperDARN Hughes J. M. 1 3 Bristow W. A. 1 Greenwald R. A. 2 Barnes R. J. 2 Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland, USA Correspondence to: J. M. Hughes (hughesj@gi.alaska.edu) 30 11 1999 20 7 1023 1030 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.ann-geophys.net/20/1023/2002/angeo-20-1023-2002.html The full text article is available as a PDF file from http://www.ann-geophys.net/20/1023/2002/angeo-20-1023-2002.pdf

Space weather effects can strongly influence high-frequency (HF) communications by changing the ionospheric environment through which the radio waves propagate. Since many systems utilize HF communications, the ability to make real-time assessments of propagation conditions is an important part of space weather monitoring systems. In this paper, we present new techniques for measuring high-latitude HF communications link parameters using data from SuperDARN radars. These techniques use ground-scatter returns to define the variation in skip distance with frequency. From these data, the maximum usable frequency (MUF) as a function of range is determined and ionospheric critical frequencies are estimated. These calculations are made in near-real-time and the results are made available on the World Wide Web. F-region critical frequencies calculated using this method show good agreement with ionosonde data.<br><br><b>Key words. </b>Ionosphere (active experiments; instruments and techniques) – Radio science (ionospheric propagation)