Initial results from DAMSON-a system to measure multipath, Doppler spread and Doppler shift on disturbed HF channels

The performance of beyond line-of-sight (BLOS) high frequency (HF) communication systems is dependent on how well the system is matched to the propagation environment. In this respect issues such as antenna gain and transmitter power are very important. Deserving equal or greater attention, however, is the issue of the match between the signalling waveform and the time and frequency spread characteristics of the propagation path. This paper briefly describes a channel sounder known as DAMSON (Doppler and multipath sounding network) which has been developed to characterise the disturbed narrow band channel (3 kHz) by measuring its scattering function. The real time nature of the DAMSON processing makes it unique in the frequency range but, in its approach to measuring the channel its operation is similar to that of Wagner et al. (1988).