Articles | Volume 20, issue 7
Ann. Geophys., 20, 1031–1038, 2002

Special issue: SPACE WEATHER

Ann. Geophys., 20, 1031–1038, 2002

  31 Jul 2002

31 Jul 2002

Nonlinear forecasts of ƒoF2: variation of model predictive accuracy over time

A. H. Y. Chan and P. S. Cannon* 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 (

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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