Analysis of diurnal variation on long-wave ground wave propagation delay

This paper aims to analyze the underlying relationships between the weather variations in a day and the propagation delay of the long-wave ground wave. First, we measured the propagation delay of the long-wave ground wave from Pucheng transmitting station to Xi'an receiving station, and found that the diurnal variation of the propagation delay is mainly related to the temperature variation in a day. What's more, we were surprised to note that there is a strong correlation between the diurnal variation of the propagation delay and the rainfall, specifically, the delay will drop sharply when it rains.