Direction finding experiment in North Scandinavia

Abstract

High-frequency (HF) radio wave propagation at high latitudes is greatly affected by geomagnetic and ionospheric conditions, and both civilian and military users need reliable forecasts of the propagation environment. In particular, the presence of large electron density gradients within the polar cap and auroral oval often lead to off-great circle propagation, which can be a serious problem for transmitter locating techniques based on direction finding and triangulation. Based on the large amount of data expected from a new Direction Finding (DF) experiment in North Scandinavia, a statistical classification of signal directional characteristics under various geophysical conditions and for all seasons can be made. In this report, cases of both quiet and disturbed geomagnetic conditions have been studied, and comparisons have been made with data from magnetic disturbance observatories in the same geographic region. In addition a first statistical study of one month of DF data is presented.