Accession Number : AD0286152

Title :   AN INVESTIGATION OF ANOMALOUS TRANSHORIZON RADIOWAVE PROPAGATION OVER IRREGULAR TERRAIN

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : CASSAM,R.

Report Date : 15 FEB 1962

Pagination or Media Count : 1

Abstract : The anomalous nighttime propagation of radio waves was studied at frequencies of 9100, 2800, and 840 Mc/s observed on the 108-km path from Rochester to Ithaca, New York. Previously proposed theories that explain anomalous propagation by ducting, reflection, or diffraction fail to explain the irregular behavior studied. Further radio measurements in the form of (1) sampling the 9100-Mc/s signal at 15 sites located along the propagation path, (2) heightgain measurements at 9100 Mc/s at the receiver site, and (3) swinging the 2800-Mc/s antennas 2 deg off the great circle path were undertaken in order to arrive at an explanation of the phenomenon. Finally, a theory based on the formation of elevated superrefractive layers situated over two lakes crossing the path is proposed to explain the anomalous propagation. (Author)

Descriptors :   *PERIODIC VARIATIONS, *PROPAGATION, *RADIO WAVES, *REFRACTION, *WATER, EXTREMELY HIGH FREQUENCY, LAKES, NIGHT SKY, SUPERHIGH FREQUENCY, ULTRAHIGH FREQUENCY

Distribution Statement : APPROVED FOR PUBLIC RELEASE