Abstract :
Illustrates high latitude effects with vertical incidence ionograms recorded in north-east Greenland (80°N, 20°W) during the operation of a HF network for short range communication, 0-600 km in a mountainous area in July 1980. The network comprised two master stations, approximately 20 field stations, three helicopters and a fixed wing aircraft. The propagation mode for the network was exclusively ionospheric reflections, as even very short distances, of 10-30 km, spanned from valley to valley, eliminating ground wave propagation. The ionogram data are compared to ionospheric characteristics published by CCIR, and the usefulness of these are discussed