Research And Implementation Of Antenna Gain Self-calibration Algorithm

Astronomy is an Observational science,and its scientific research depends on high-precision observation results.Due to the restriction of the observation environment and instruments,the observation results of all current astronomical instruments have different degrees of error.It is an important content of astronomical technology research and development to calibrate the observed data and improve the reliability of scientific data.The Square Kilometre Array(SKA)is the world's largest radio telescope currently under construction,with extremely high time,space and frequency sensitivity,and is able to observe very faint signals from the early universe.Its completion will bring more new discoveries to scientists and greatly advance our understanding of the formation and evolution of the universe.The problem,however,is that the SKA is vulnerable to a variety of weak and complex systems and environmental effects that can drastically reduce the accuracy of observations.In order to improve the image quality,how to effectively calibrate the antenna gain in the radio interferometer array is one of the important research contents in the data processing of modern radio interferometer array,and it is also the core problem in the construction of SKA telescope.In this paper,the basic principle of antenna gain calibration in self-calibration is introduced.Then,the classical antenna gain calibration algorithm Antsol is implemented based on pure Python.The code implemented has been integrated into SKA-RAs CIL and will provide important support for imaging calibration of SKA.At the same time,the Python program optimization method used in the code implementation will also provide reference for the development and performance optimization of other astronomical software.In addition,the simulation data of SKA1-LOW and real observation data of Mingantu Spectral Radioheliograph(MUSER)are used to test and compare Antsol and StEFCal algorithms.Experimental simulation and actual observation results show that the proposed method achieves high precision and can meet the data processing requirements of SKA antenna gain self-calibration.The results of this study have good reference value for the follow-up work of SKA and the development of other radio astronomical interferometers in China.