The study of phase closer of Mingantu Spectral Radioheliograph

Abstract

Mingantu Spectral Radioheliograph (MUSER) is a key instrument supported by the Chinese National Major Scientific Equipment R&D Project. It is a new generation solar-dedicated telescope and will play an important role in solar physics, space weather prediction, and even space missions. MUSER is a solar-dedicated radio interferometric array with 100 parabolic antennas. It is very complex to calibrate the whole system, including amplitude- and phase-calibration. Among them, the phase closure is one of the special important procedures of the whole system. In this paper, we proposed a new method to measure the phase closure, ensure the veracity of the correlation function and test the stability of the whole system of MUSER. We adopted the Geostationary Communications Satellite to be the calibration sources, fixed the antenna's point with the same parameter of delay compensation. We calculated position correction of the satellite spherical coordinates. Then the phase variation can be measured precisely. The calculating processes of cross-correlation is among different 3-baseline. The phase closure is better than 3 degrees. These results meet the requirements of the phase calibration of MUSER.