Heliograph of radio decameter wavelengths

The heliograph of radio decameter wavelengths started to be created and developed else in 1976 on the base of antenna system UTR-2 (Ukrainian T-shaped radio telescope). Basically, the main features of the heliograph are determined by the characteristics of UTR-2. To observe stars, Sun, planets and others within the frequency range 10 – 30 MHz, the radio telescope forms five independent pencil-shaped beams with angular width 25′ × 25′. The scanning of sky area is provided discretely in declination and hour angle. The sensitivity of heliograph is about 104 Jy (1 Jy = 10−26 W/m2/Hz). At first the radio astronomy observations by the radio telescope UTR-2 (and the heliograph too) were carried out at a few discrete frequencies. This led to difficulties in distinguishing solar burst features (for example, fine structure of the solar Type II bursts and so on) with confidence. Last time the facilities of radio telescope UTR-2 have been essentially extended due to an effective broadband telescope amplifier system and a new back-end. Now the observations are conducted by means of the DSP (digital spectrum processor) in the frequency band of 16.5 MHz divided on 4096 channels. Therefore, the basic scheme of the heliograph and its properties have been improved.