A New Position Calibration Method for MUSER Images

Abstract The Mingantu Spectral Radioheliograph (MUSER), a new generation of solar dedicated radio imaging-spectroscopic telescope, has realized high-time, high-angular, and high-frequency resolution imaging the Sun over an ultra-broadband frequency range. Each pair MUSER antennas measures complex visibility in aperture plane for each integration time channel. corresponding image channel is then obtained by inverse Fourier transformation data. However, phase severely corrupted instrumental propagation effects. Therefore, robust calibration procedures are vital order to obtain high-fidelity images. While there many techniques available—e.g., using redundant baselines, observing standard cosmic sources, or fitting disk—to correct data above-mentioned errors, configured with non-redundant baselines disk structure cannot always be exploited. Therefore it desirable develop alternative methods addition these available whenever appropriate reliable In case where point-like source contains unknown position error, we have first derived mathematical model describe problem proposed optimization method calibrate this error studying offset positions images certain period interval. Simulation experiments actual observational analyses indicate that valid feasible. For MUSER’s practical calibrated errors within spatial angular instrument. This can also used other situations synthesis observations.