الفهرس 
The hertz vectorOnly 14 pages are availabe for public view
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Abstract
The el-aporation duct model used is that of Kallan and Eckart and consists of a discontinuous DROP of the otherwise constant relative pennitti\-ty at the upper duct bo~uldaq-T. he earth is assumed to be a peifect conductor and idcally plane. We determine the electrical field strength exactly at some fixed point above the duct layer, having chosen a certain polarization of the prim-. source whose moment is allowed to vary arbitrarily in time. The method used for solution is essentially based on the application of two hlctional transforms to the wave equation of the electric field strength. A Laplace transfonn in tiine and a two-dimensional Fourier transfonn in the horizontal coordinates in space leads, under consideration of initial, boundary and transition conditions, to an integral representation of the solution of the wave equation 111 the transform space. A series expansion with respect to the images of the prllnary source permits us to extend the method of Cagniared, and exqended by de Hoop and Frankena, to the case where the position of the source is in the me&m of lesser permittivity. The field strengths of the image sources combine to the total field strength with different signs for the two polarizations apart from the fact that they are of different mathematical stnlcturs. Hence we can give a physically intuitive description of the polarization dependence of the tiine history of the electrical field strength.