Research on High-precision Fiber Transmission and Compensation for a Solar Radio Heliograph

Abstract Solar radio bursts are a major source of space weather hazards. Thus, developing solar observation systems is essential. The heliograph, based on synthetic aperture imaging and a dual interferometer, enables high-resolution solar imaging, offering rich spatial information beyond conventional radio spectrometers. The performance of a synthetic aperture heliograph depends critically on time-frequency synchronization among multiple antennas. On this basis, we have conducted research on fiber time-frequency synchronization. The research allows the long-distance transmission and synchronization of signals generated by the rubidium atomic clock via optical fiber. Analysis and testing demonstrated that the research achieved frequency stability of 7 × 10 −13 /1 s and an accuracy of 0.466 ppm. After compensation, the average time difference achieved 4.6 and 5.4 ps for frequency and time standard signal, respectively. These results not only indicate that our scheme meets the requirements of the synthetic aperture heliograph but also demonstrate good applicability and scalability, providing a solid foundation for the future development of solar observation systems.