A method for estimating the scattered component of an HF signal during vertical ionospheric sounding

The parameter beta (2) = signal/noise and the collisionless damping L-s of coherent radiation are estimated from vertical sounding of the F region at the Rostov midlatitude station (47 degrees N, 39 degrees E). A method that is based on recording signal quadrature components and that does not requir e any knowledge of the statistical distribution laws for the wave field is used [1]. The reflected signal has been found to be dominated by incoherent radiation (beta (2) < 1 or <beta>(2) much less than 1). This is indicative of multiple wave scattering in the F region and leads to a heavy attenuati on (of the order of 10 dB) of the coherent signal field component.