Abstract
Radio telescopes are renowned for their high sensitivity and resolution. However, subtle electromagnetic interference from internal sources within the observatory site can considerably disrupt their operational state, thereby aggravating the challenges associated with astronomical observations. This study addresses the issue of near -field coupling induced by transient radiation interference from internal sources within the observatory site of the 110-m radio telescope. For this purpose, a hybrid calculation method based on dipole approximation and time -domain physical optics is proposed. The analysis commences with a meticulous examination of transient radiation interference emanating from internal sources at the observatory site. Leveraging the principles of dipole antenna theory, the near -field radiation sources are analyzed and accurately modeled. By integrating the time -domain physical optics approach, the electromagnetic coupling characteristics of the internal sources of radiation interference on the near -field aperture plane of the radio telescope are comprehensively analyzed and quantified. Finally, the efficacy of the proposed method is validated using the FEKO full -wave algorithm. The proposed method serves as a theoretical foundation for analyzing the influence of interference from internal sources of radiation at the observatory site on the astronomical observations of the 110-m radio telescope.