The helioseismological CORONAS-F DIFOS experiment

The CORONAS-F DIFOS experiment continues the CORONAS-1 studies started in 1994, devoted to investigations of solar global oscillations. CORONAS-F was launched July 31, 2001. Variations in the intensity of the solar radiation are measured in the six spectral intervals of the multi-channel photometer: 350, 500, 650, 850, 1100, and 1500 mm, with the bandwidths being about 10% of the central wavelength of each interval. The scientific goals of the experiment, a brief description of the instrument, and observational conditions are presented, as well as the data processing techniques. The first observations of the low-order p eigenmodes of the solar oscillations are presented for various wavelength ranges. A decrease in the relative amplitudes with observing wavelength is indicated. The amplitude ratios for various spectral ranges agree well with those detected earlier in ground- and space-based experiments. (C) 2004 MAIK "Nauka/Interperiodica".