VLF ionospheric reflection coefficients-Derivation from impedance concepts and values for some model ionospheres

A convenient general method is presented for computing the reflected wave excited by an arbitrarily polarized, plane, VLF electromagnetic wave incident at an arbitrary direction upon a sharply bounded, absorptive ionosphere in the geomagnetic field. The relative simplicity of the method results from the use of impedance concepts coupled with Booker's treatment of the propagation vector. Expressions for reflection coefficients are given that are exact (for the model assumed) in the case of propagation perpendicular to magnetic meridians and indicate clearly lack of east-west and west-east reciprocity. The results of calculations for eight model ionospheres are given in the form of graphs of reflection coefficient amplitude and phase versus angle of incidence for both east-west and west-east propagation at 16 kc/sec. The model ionospheres are characterized by values of electron density and collision frequency. A brief relation is made between the computations and some experimental results.