An Investigation into the Correlation Between Signal Path Variation and Structural Deformation in Large Radio Telescopes

Signal path variation in radio telescopes is a critical factor affecting observational accuracy, with structural deformation-induced path changes representing a primary error source. In Very Long Baseline Interferometry (VLBI) observations using large telescopes, such deformations introduce signal delays that compromise measurement precision, especially in high-accuracy applications like geodesy and spacecraft tracking. This study systematically investigates signal path variation patterns induced by structural deformations through theoretical analysis and experimental validation, focusing on four key mechanisms: gravitational deformation of main/sub-reflectors, thermal expansion/contraction of the main reflector, offset-axis structural configurations, and antenna pointing errors.