HF NVIS kommunikasjon - kanalkarakteristikk på høye breddegrader

The HF DAMSON (Doppler And Multipath SOunding Network) was operated on two NVIS (Near Vertical Incidence Skywave) paths in northern Scandinavia during two measurement campaigns in October 1999 and March 2000, respectively. Channel measurements on the two paths Harstad-Abisko (90 km) and Harstad-Kiruna (190 km) have been analyzed in terms of signal-to-noise ratios, signal strength, Doppler and delay spread. These channel parameters can seriously affect the performance of communications. High latitude channel characteristics versus time of day, frequency and geomagnetic conditions are described in the report and the two paths are compared. Also, the variability of one particular frequency is addressed.