Design and performance of a system for the derivation and analysis of HF channel state data

The paper describe techniques by which an HF channel impulse response measurement capability can be added to existing ITU broadcast field strength monitoring terminals. This additional capability can be provided via a simple software upgrade. Obviously, due to the relatively low clock rate of the complementary sequences and the restricted transmission bandwidth, the time resolution of the impulse response estimate is somewhat limited. However, the resolution is sufficient to identify the multipath conditions which are likely to have a detrimental effect on the majority of HF data modems.