A Super-resolution Analysis Method for Ionospheric Scattering Function

The observation of the ionosphere is of great significance for geophysics, radio propagation mechanisms, and related engineering applications. In response to the low range and Doppler resolution of the scattering function map obtained by traditional ionosonde with fewer coherent soundings, this letter proposes a super-resolution analysis method. By utilizing the coherence between the frequency components of the echo signal and using phase weighted summation, the super-resolution synthesis in the range dimension was achieved. In the frequency dimension, the Capon spectral super-resolution estimation method was employed. In this way, super-resolution is achieved both along the range and Doppler axis of the scattering function map simultaneously. It breaks the limitations of spatial and temporal sampling rates on observation resolution. Simulation and experiment results have verified the performance of this method. With a tenfold increase in resolution, it achieves the distinction of multi-layer echo traces and the identifies their subtle Doppler difference. This method provides a favorable means for efficient and accurate detection of the ionosphere.