Properties of 400 Mcps Long-Distance Tropospheric Circuits

Measurements are reported on beyond-the-horizon propagation losses at 400 Mcps. Data are given on the losses and their variations from 98 to 830 mi beyond the horizon. The transmission loss between isotropic antennas varies from about 190 db at 100 mi to about 300 db at 800 mi distance. Also described are measurements of frequency-selective fading, space diversity, and variations in the angle of arrival of the signals.