Panoramic Analyzer of Radio Spectra — Instrument for Measurements of Coronal Magnetic Fields on the Sun

Abstract

The study of solar radio emission in a wide (covering many octaves) wavelength range is of great importance for plasma diagnostics of all types of solar activity. Here we describe a new spectroanalyzer covering a wide range in frequency from 1 to 18 GHz, which is used at the RATAN-600 radio telescope beginning 1991 December 20. Coronal magnetic fields have been measured with the various radio astronomical methods presented in these proceedings by Gelfreikh et al. and Bogod et al.Of special value are collaborative spectral-polarization observations using the RATAN-600 and high-spatial resolution observations with the VLA and WSRT (Akhmedov et al. 1986; Bogod et al. 1992; Alissandrakis et al. 1992).

Analysis of the Multiple Inversion of Circular Polarization in Solar Microwave Local Sources

“…1). The inversion is not as pronounced as in the case of double inversion in AR 6996, 1992, discussed by Bogod et al (1993b), and seems to be dependent on the reduction procedure of radio observations. Hence, some complementary criteria should be elaborated for recognition of the reality and the multiplicity of the multiple inversion.…”

“…4a) Our attempts to fit the observed polarization inversions and the wave mode coupling theory have made it evident that: -ARs 145+152 SD, 1992 (Figs. 1 and 4a) demonstrate fourfold rather than twofold inversion; -the inversion in AR 6996, 1992, earlier considered to be twofold (Bogod et al 1993b), does not obey the restrictions of Section 3 ( Fig. 4b) and needs further analysis; -the inversion in AR 62 SD, 1977, detected with smaller number of radio receivers comparing to PAS (Fig.…”

“…Now we will analyze the depression of circular polarization at wavelengths close to the wavelength of the polarization inversion (zero circular polarization). Let us assume that a set of radio observation wavelengths can be written as follows: A¿4-1 = A, -+ e • Aj, i -1,2,3,...,m. In the case of PAS of the radiotelescope RATAN-600, £ = Omandrn = 27 (Bogod et al 1993b). If the wavelength of the inversion is Aj (p(\i) = 0), then according to Eq.…”

“…Double inversion of the circular polarization was detected for the first time by Bogod et al (1993a) in the spectral polarization observations with a new Panoramic Spectrum Analyzer (PAS, see Bogod et al 1993b) of the RATAN-600 radiotelescope on January 9-10, 1992. It was attributed to the electromagnetic mode coupling in the regions of the quasi-transverse propagation in the solar corona (hereafter, QT-regions) (Zheleznyakov 1970).…”

About the nature of long‐term microflare energy release in solar active regions

“…The observations with the radio telescope RATAN-600 were carried out with the use of a wideband panoramic spectrum analyzer in the range 0.95-16.7 GHz in 35 frequency channels [Bogod et al, 1993]…”