Standing wave pattern of HF radio waves in the ionospheric reflection region. Part 1: General formulas

Formulas for computing the field strength near the reflection point of an electromagnetic wave impinging vertically upon a horizontally stratified ionosphere are derived by a uniform approximation valid throughout the whole reflection region. Smoothly varying profiles of general shape but with the gross features determined by the presence of one or two transition points are assumed. Coupling and nonlinear effects are not explicitly included. The formulas can be used to calculate the field structure of HF radio waves transmitted into the ionosphere and to calculate the swelling of reflected waves.