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Ann. Geophys., 20, 1031-1038, 2002
www.ann-geophys.net/20/1031/2002/
© European Geosciences Union 2002
Nonlinear forecasts of ƒoF2: variation of model predictive accuracy over time
A. H. Y. Chan and P. S. Cannon*
Centre for RF Propagation and Atmospheric Research, QinetiQ, Malvern, UK
*Also at the Department of Electronic and Electrical Engineering, University of Bath, UK
Correspondence to: A. H. Y. Chan (achan@QinetiQ.com)
Abstract. 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.
Key words. Ionosphere (active
experiments; instruments and techniques) – Radio science (ionospheric
propagation)
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