Methods of Radio Frequency Interference Mitigation on the Stage of Preliminary Processing of Received Signals

Abstract

Subject and Purpose.Methods for computer processing of radio astronomical signals observed with space objects at low frequencies are given. The aim of this paper is to improve the current methods and use their combinations for cleaning records from radio interference of natural and artificial origin in the frequency-time domain, as well as to discuss advantages and disadvantage of the methods. Methods and Methodology.In the study of records obtained with radio astronomical observations there is a common feature of received signals from space sources, which consists in a significant contribution of radio interference. Having sufficient experience on possible types of interference and distortion of signals on the way of their propagation, the efficiency of suggested procedures, clearing radio signal interference in the frequency-time domain by a combination of different approaches in dependence from typical features of signals withinvestigated space objects, is shown. Results. The developed methods of extracting space signals against the background of interference allow one to get unique data on the sources of radio emission in astrophysical phenomena. On the one hand, software tools make it possible to detect very weak events against the background of radio frequency interference. On the other hand, they allow one to measureemission parameters based on the most statistically complete set of events. Conclusions.The results obtained in this work manifest that there is no universal way to overcome any obstacle in the records of radio astronomical observations because of radio interference. In addition, even if the most appropriate method is applied, it often requires pre-adjustment of the corresponding parameters on which the analysis of physical parameters of radio emission in the area of generation depends. But if such a space signal at the radio records is not very spoiled by interference, the use of considered methods can be successful and useful.

Mitigating Interference in Dynamic Spectra in the Presence of Powerful Signals Part 1. Powerful Broadband Pulses and Linear Frequency-Modulated Interference

“…У цій роботі не обговорюються питання, пов'язані з подальшою обробкою корисного сигналу, де завади не було виявлено, або методи заміщення завад шумовими або іншими сигналами, наприклад, за допомогою інтерполяції [15]. Все це, безсумнівно, становить великий інтерес для майбутніх досліджень.…”