A New 17-GHz Solar Radio Interferometer at Nobeyama

Abstract

Abstract A description is given of a new 17-GHz solar radio interferometer of the Nobeyama Solar Radio Observatory. The design of the interferometer is based particularly on the following two requirements : to achieve a time resolution high enough to follow rapidly changing phenomena such as impulsive bursts, and to make adjustment of the phase and gain as accurately and frequently as possible. These two requirements are satisfied by adopting both a multi-correlator receivingsystem and a self-calibration system which makes use of redundant Fourier components of a compound type array. The interferometer is able to produce east-west images of the whole Sun with a time resolution up to 0.8 s for two circular polarizations. The spatial resolution is ~45″. The sidelobe levels can be reduced to ≤3% under a good condition, when the average calibration errors of antenna channels are estimated to be ~3° in phase. The successful operation of the present calibration system guarantees a further development of a higher spatial resolution of a few arcseconds. Some examples of initial observations are presented.