Determination of dispersive bandwidths characteristic for the propagation of HF pulses via the ionosphere

Discusses the range of the dispersive bandwidths characteristic for HF pulses propagating through F region of the ionosphere as determined both by the simulation technique and the analysis of ionograms. It is found to be from 20-190 kHz. It is noticed that variation of the dispersive bandwidths from case to case of propagation is similar whether calculated or deduced from ionograms, although the results from the two methods, for particular pulses can differ up to 50%. A better agreement probably could be obtained if the simulation technique is applied to the determination of the second total derivative of the group path with respect to frequency, and if a ray path more realistic than mirror reflection ones are considered in calculations based on the ionogram analysis. The discrepancy between results obtained by the simulation technique and the analysis of ionograms for the E region pulse propagation, is under 10%. The best agreement is in the cases of the propagation via thick sporadic-E, because the mirror type reflection is present