Error Correction And Application Research Of Single-station Lightning Location Syste

The real-time lightning location,the monitoring and early warning of thunderstorm activity are of great practical significance.However,the construction of multi-station lightning location system relies on a high-precision time system and good network communication capability,which cannot be met in some cases,but there is still a demand for monitoring and early warning of thunderstorm processes.The ground wave arrival time delay caused by the propagation effect and the site-error inherent in the magnetic direction finder method will affect the accuracy of single-site lightning location.In this study,a single-site lightning location system is established.The analytical method is used to obtain the relationship between the ground wave arrival time delay and the propagation distance,and it is used to correct the time difference between the peak points of the skywave and the ground wave in the lightning waveform,which improves the distance estimation accuracy of the single-site lightning location system.Then,the multi-station lightning location data is used to calculate and revise the siteerror,and the location accuracy and efficiency of the revised location results are evaluated.The Spatiotemporal-Ordering points to identify the clustering structure(ST-OPTICS)clustering algorithm is used to cluster the single-site lightning location results and evaluate its ability to monitor thunderstorm activity.The main research results of this paper are as follows:(1)It was found that there is a positive relationship between the ground wave arrival time delay and the propagation distance by using the analytical method.When the soil conductivity is 0.01S/m,the average delay in the arrival time of the ground wave peak point is 0.9μs for every 100 km increase in the propagation distance.The site-error in the magnetic direction finder method is statistically obtained by using the multi-station lightning location results,and the mean deviation of the azimuth angle calculated using the skywave peak are smaller and more concentrated compared with those calculated using the ground wave peak,and the siteerror distribution shows a bi-periodic variation related to the azimuth.After correcting the siteerror,the average deviation of single-site magnetic direction finder results decreases from 12.3°to 8.6° and 80% of the azimuthal deviations are less than 11.5° compared to the multi-station lightning location results.(2)After correcting the ground wave arrival time delay caused by the propagation effect,the multi-station lightning location results were used to invert the ionosphere equivalent reflection height.It is found that the ionosphere equivalent reflection heights of the two study areas in this paper are basically the same at night,between 84 km-87 km,while they are between 69 km-72 km and 73 km-75 km,respectively,during the daytime.(3)Through comparison with the multi-station lightning location results,it is found that the effective detection range of the single-site lightning location system is 200km-2000 km,and the average deviation of the lightning distance estimation is 7.9% to 17.0%.Considering the azimuth deviation,the final deviation range of the single-site lightning location system is 8.4%to 18.6%,and the detection efficiency of single-site lightning location system is about 38.8%.(4)After using the ST-OPTICS algorithm to cluster the single-site lightning location results,it is found that the cloud top temperature in the regions where the clusters are located is between 195 K and 240 K,which proves that the single-site lightning location system can better monitor thunderstorm activities.For thunderstorm process in different regions,the single-site lightning location system in Nanjing can monitor the whole process of thunderstorm activity more completely,and the characteristics of the monitored thunderstorm activity are similar to those given by the multi-station lightning location system.