Inversion of ground conductivity using eLoran signal characteristics

Ground conductivity is an important physical parameter that reflects the earth's electrical conductivity. Low-frequency signals propagate along the earth's surface, and ground conductivity is a key factor affecting their propagation. Accurate ground conductivity helps analyze and study the propagation characteristics of low-frequency radio signals; conversely, the propagation characteristics of low-frequency radio signals can be used to inversely derive ground conductivity.This paper utilizes the characteristics of eLoran signals—field strength and time delay—to inversely derive ground conductivity, presenting simulation analyses and experimental results. The research findings demonstrate that using eLoran signal characteristics to invert ground conductivity is feasible, and the inversion results are reliable. The ground conductivity derived from field strength inversion is more suitable for field strength calculations, while the ground conductivity obtained from additional secondary factor (ASF) inversion is more applicable to secondary time delay calculations.Additionally, due to the complexity of signal propagation paths, the accuracy of conductivity inverted over medium to long distances is slightly lower than that over short distances. To address this, a segmented inversion approach is proposed, which will be a key focus of subsequent research efforts.