Range detection improvement for Irkutsk Incoherent Scatter Radar measurements with Barker code modulation

Barker codes are widely used in incoherent scatter (IS) radars, particularly for tasks requiring a significant improvement in spatial resolution. However, sidelobes in the response structure of the correlation processing filter to the probing signal lead to a reduction in the informativeness of ionospheric plasma parameter measurements. This paper investigates the application of a sidelobe-free (SLF) filter for processing signals from the Irkutsk IS radar (IISR). We compare the SLF method with standard matched filtering by analyzing experimental data. The study shows that the SLF filter effectively suppresses sidelobes, which improves the identification of interference from space vehicles and allows for the separation of closely spaced ground clutter sources with improved range resolution. Applying the SLF filter to electron density profile recovery via Faraday rotation demonstrates increased robustness and accuracy, particularly for short integration time (1–2 min). The results confirm that implementing SLF processing for IISR measurements increases the range detection of weak signals and improves spatial resolution from 30 to 6 km by mitigating the masking problem.