SuperDARN scalar radar equations

Abstract

The quadratic scalar radar equations are obtained for Super Dual Auroral Radar Network (SuperDARN) radars that are suitable for the analysis and interpretation of experimental data. The paper is based on a unified approach to obtaining the radar equations for the monostatic and bistatic sounding with the use of Hamiltonian optics and ray representation of scalar Green's function and without taking into account the polarization effects. The radar equation obtained is the sum of several terms corresponding to the propagation and scattering over the different kinds of trajectories, depending on their smoothness and the possibility of reflection from the ionosphere. It is shown that the monostatic sounding in the media with significant refraction, unlike the case of refraction‐free media, should be analyzed as a combination of monostatic and bistatic scattering. This leads to strong dependence of scattering amplitude on background ionospheric density due to focusing mechanism and appearance of new (bistatic) areas of effective scattering with significant distortion of the scattered signal spectrum. Selective properties of the scattering have been demonstrated as well.

Identifying ground scatter and ionospheric scatter signals by using their fine structure at Ekaterinburg decametre coherent radar

“…During several tens of milliseconds (corresponding to characteristic repetition period of sounding pulses and consequently to minimal lifetime of elementary response that can be detected) both variate slow. Within the quantitative approach (Berngardt, Kutelev, & Potekhin, 2016), the regions of effective scattering are also the regions with a given level of refraction and with satisfied aspect sensitivity conditions. So, the positions of the regions should not change during several tens of milliseconds.…”

Analysis of the fine structure of HF ground backscatter and ionospheric scatter signals based on EKB radar data

“…The assumption we made about the stationarity of the scatterer position is more strict. From qualitative considerations, it can be justified as follows: within the radar equation in presence of refraction [Berngardt et al(2016)], the locations of effective scattering that are equivalent to the scattering at a point object are the locations with a given level of refraction in which at the same time an aspect sensitivity conditions are satisfied. Thus, their positions in the first approximation are determined by relatively large-scale structure of the ionosphere and the magnetosphere and have a relatively slow dynamics.…”