Measurements of the delay, Doppler and directional characteristics of obliquely propagating HF signals over several northerly paths and a comparison with vertical ionosonde and HF radar observations

The high latitude ionosphere is a very dynamic and disturbed region containing irregularities which, on scales much greater than a wavelength, may be considered as providing a rough reflecting surface for obliquely propagating HF radiowaves. To improve our knowledge and understanding of the complex propagation mechanisms prevalent in the high latitude region, an experimental campaign is currently being conducted with a receiver system capable of measuring the delay and Doppler spread characteristics and the directional structure of the received signals at Kiruna in northern Sweden.