New HF spectrum occupancy measurements in Southern England

Selected measurements of the HF fixed service bands are being carried out at a field site in southern England near the Rutherford Appleton Laboratory as part of a programme of ongoing study. This paper presents recent sample results of amplitude probability distributions (APDs) and unoccupied channel duration statistics using a single vertical whip (omnidirectional) receiving antenna and a filled array beamed either to the N or S. Data interpretation takes advantage of the extensive work carried out since the 1970s on the modelling of man-made interference and signal fading. >