Fading characteristics observed on a high-frequency auroral radio path

Abstract

Obsen·ations of f,.d ing chamcLeri sLics of h igh-frequency sig na,ls have been carried ou t on a long path (4,470 ki lometer,) pass i ll '~ Llnoug h the a uroral zone. SLaListics were obLain ed on fad ing rate, shor t-Lern1. carrier amp liLud e flu ctuaLio ns, and fad e duraLio ns. Fad in~ raLes higher than 20 c:vcles per seco nd were observed for a s mall percenLage of Lhe time at eac h of the t hree carrier frequencies u sed , >Lnd show only a minor d itlrnalLrend, wiLh lhe maximum usually occu rring during t he early morning h ours. Rayleigh di sLribuLions of carrier envelope ampli Lude were obtain ed for man y of the obse rvaL ions; however , fading d epLh was normally reduced durin g periods of rap id fad ing.