REPRESENTATION OF PROPAGATION MODE FADING FOR THE MIDLATITUDE WIDE BANDWIDTH HF CHANNEL

MITRE has made measurements of the wide bandwidth (1-MHz bandwidth) im pulse response of HF propagation modes for midlatitude paths in the Un ited States. These paths included near-vertical incidence, 2000 and 30 00 km lengths, and primarily supported one-hop F layer propagation. On the basis of these measurements, this paper proposes a stochastic rep resentation for the path loss fluctuation of propagation modes observe d for 15-min time intervals. When expressed in decibels, this path los s is modeled as a normally distributed autoregressive process of low o rder. Estimates of the parameters for this model are extracted from th e data for a variety of transmission conditions. A model order of 1 is suggested for link modeling.