Lower atmospheric duct monitoring based on ground-based GNSS occultation signal

The atmospheric duct has a significant impact on the propagation of ultra-short and the above radio waves. In order to solve the problem of real-time acquisition of the parameters of the marine atmospheric duct, it is proposed to extract the environmental information of the marine atmospheric duct from the received signals of the ground-based GNSS satellite occultation process. The parabolic equation method is used to realize the forward model for predicting the received power of ground-based GNSS occultation signals from ducting parameters. Through combining the forward model, the parameterized atmospheric duct model and the objective function with genetic algorithm, the inversion algorithm of ducting parameters based on the received power of GNSS occultation signal is realized. The influence of standard refraction, surface duct and elevated duct on GNSS occultation signal received near the ground is simulated. Through experiments, the measured occultation signals of Beidou, GLONASS and GPS under different refraction environments are obtained, and the measured GNSS occultation signals are used to retrieve the low-altitude atmospheric duct. The results show that the adopted method can effectively monitor and retrieve the low-altitude atmospheric duct, which has the characteristics of passive remote sensing.