The attenuation of a specular component of HF signals from the vertical sounding of ionosphere

The turbidity of the ionosphere for a passing electromagnetic radiation is described by the signal-to-noise ratio β²=I ₀/⟨I_s⟩, which is the ratio of specular I ₀ to ⟨I_s⟩ ensemble average scattered components of the wave field. The main method of β² estimation currently used is the approximation of experimentally obtained amplitude distribution laws of the waves reflected by the ionosphere with the aid of certain theoretical models. However, the same data, obtained from vertical F-region sounding, are described well enough by different models and lead to different β² values that differ by several orders (Denisenko et al. 1993). In this paper, a new method for β² value determination is proposed. No assumptions about the amplitude distribution law of the waves reflected by the ionosphere are required. This method leads to a correct estimation of the attenuation L_s of specular component of the wave field, coupled with β² by L_s =ln((1+β²)/β²)