Accession Number : ADA262932


Title :   Whispering Gallery Effects in the Troposphere


Descriptive Note : Journal article


Corporate Author : NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN DIEGO CA


Personal Author(s) : Hitney, H V


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a262932.pdf


Report Date : Dec 1992


Pagination or Media Count : 8


Abstract : Experimental data that recorded higher-than-expected signals at 3087. 7 MHz far beyond the horizon in the presence of an elevated duct are examined and compared to results from the radio physical optics (RPO) propagation model. RPO is a range-dependent hybrid model that combines ray optics and parabolic equation methods. Previous modeling of this same case study using waveguide methods for both the measured elevated duct and hypothetical evaporation ducts has been disappointing. However, when the elevated duct is allowed to rise slowly with increasing range, the RPO results closely match the observed signal levels, indicating that weakly attenuated Earth-detached, or whispering gallery, modes were the dominant propagation mechanisms.


Descriptors :   *WAVEGUIDES , *WAVE PROPAGATION , VELOCITY , REPRINTS , OPTICS , SPHERES , COMMAND AND CONTROL SYSTEMS , ENVIRONMENTAL TESTS , TROPOSPHERE , HORIZON , WAVE EQUATIONS , ATMOSPHERIC REFRACTION , TACTICAL DATA SYSTEMS , RADIO SIGNALS , DECISION AIDS , RADIO EQUIPMENT , CASE STUDIES , BOUNDARIES , EXPERIMENTAL DATA , MODELS , WAVEFORMS


Subject Categories : Radiofrequency Wave Propagation


Distribution Statement : APPROVED FOR PUBLIC RELEASE