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The present state of solar wind investigations by IPS (interplanetary scintillations) observations at decameter wavelengths is discussed. Radio telescopes, equipment and methods which are used in these experiments are shown. We also describe some interesting results devoted to the long term monitoring of the solar wind beyond Earth’s orbit, the detection of the large scale disturbances associated with active processes at the Sun and the reconstructions of the solar wind stream structure. Emphasis is placed on perspectives of low frequency IPS investigations which are particularly connected with the creation of the Giant Ukrainian Radio Telescopes (GURT) and UTR-2 – URAN – GURT – LOFAR collaboration.

According to the special Program of the National Academy of Sciences of Ukraine, creation of the new giant Ukrainian radio telescope (GURT) was started a few years ago on the UTR-2 radio telescope observatory. The main goal is to reach maximum band at the lowest frequencies (10-70 MHz), effective area (step-by-step up to 100,000 sq.m), and high interference immunity for resolving many astrophysical tasks when the sensitivity is less limited by the confusion effects. These tasks include stellar radio astronomy (the Sun, solar wind, flare stars, pulsars, transients) and planetary one (Jupiter, planetary lightnings, Earth ionosphere, the Moon, exoplanets). This array should be complementary to the LOFAR, E-LOFAR systems. The first stages of the GURT (6 x 25 cross-dipole active elements) and broad-band digital registration of the impulsive and sporadic events were tested in comparison with the existing largest decameter array UTR-2.

In this paper, test results from a 25-element active antenna prototype array operating in the frequency range of 10–70 MHz are presented. Observations of radio emission from different sources: solar sporadic radio emission and powerful cosmic radio sources including their ionosphere scintillation, demonstrate the high effectiveness of the system due to the Galactic background limited sensitivity and high dynamic range of the antenna amplifier (noise immunity). This demonstrates the capability of this 25-element active antenna array to engage in a wide range of unique wide band radio astronomical observations of solar system objects that do not require high sensitivity and angular resolution.