The analysis of HF propagation by means of Kirchhoff integral techniques

For isotropic media, reciprocity relations can provide a foundation for techniques for calculating radiowave propagation. These give rise to the well known Kirchhoff integral methods and these have been successful for analysing terrestrial propagation. It is shown in this paper that such techniques can also be used for calculating propagation in the ionosphere when magneto-ionoic effects can be ignored. In the case of non-isotropic media, however, there are `pseudo´ reciprocity relations that can also provide a foundation for techniques for calculating propagation. Consequently, it is also possible to extend Kirchhoff integral techniques to include magneto-ionic effects.