We report about observations of solar U+III bursts on 2020 June 5 by means of a new active antenna designed to receive radiation in 4–70 MHz. This instrument can serve as a prototype of the ultra-long-wavelength radio telescope for observations on the farside of the Moon. Our analysis of experimental data is based on simultaneous records obtained with the antenna arrays GURT and NDA in high frequency and time resolution, e-Callisto network as well as by using the space-based observatories STEREO and WIND. The results from this observational study confirm the model of Reid and Kontar.

We present the 25-element active antenna array and its remote control in the framework of the GURT project, the Ukrainian Radio Telescope of a new age. To implement beamforming, the array is phased with the help of discrete cable delay lines in analog manner. The remote control of the array is carried out through the paired encoder and decoder that can transmit parallel data about antenna codes serially. The microcontroller provides the online interaction between personal computer and beamformers with the help of the encoder-decoder system through wires or wireless. The antenna pattern has been measured by radio astronomy methods.

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.

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