The Geometrical Optics of VLF Sky Wave Propagation
- 1 June 1957
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in Proceedings of the IRE
- Vol. 45 (6) , 754-760
- https://doi.org/10.1109/jrproc.1957.278468
Abstract
At distances not exceeding 1500 km, it is convenient to calculate the field strength of a vlf transmitter by geometrical optics. In such computations, it is usual to assume some equivalent height for the (ionospheric) reflecting layer with a reflection coefficient that does not vary with angle of incidence. In the present paper, the ionosphere is taken to be a homogeneous ionized medium with a sharp lower boundary. The reflection coefficient, which is a function of angle of incidence, is utilized to compute the strength of the single and multiple hop sky waves. Combining these with the numerical results of the amplitude and phase of the ground wave, the total field is obtained. The theoretical field-strength-vs-distance curves compare favorably with the experimental data of Heritage for frequencies of 16.6, 18.6, and 19.8 kc over daytime paths in the Pacific Ocean. Finally, diffraction by the earth's bulge of the first hop sky wave is considered. This effect is important at ranges greater than 1200 km or so.Keywords
This publication has 3 references indexed in Scilit:
- Pattern of a flush-mounted microwave antennaJournal of Research of the National Bureau of Standards, 1957
- Multiple reflections between the earth and the ionosphere in V.L.F. propagationPure and Applied Geophysics, 1956
- CXVIII. The propagation of a radio atmospheric—IIJournal of Computers in Education, 1952