| Lightning is a complex strong discharge phenomenon in the atmosphere.The high voltage,transient high current,and strong electromagnetic radiation associated with lightning often cause serious disasters and economic losses.The research on lightning monitoring and location is of great significance for reducing lightning disasters.Lightning locator is a meteorological detection device that uses the electromagnetic field characteristics of lightning return stroke radiation to remotely measure lightning return stroke discharge parameters.It can monitor the time,location,intensity,polarity,etc.of lightning occurrence.Location accuracy is a key technical index for evaluating lightning location networks.Aiming at the lack of theoretical guidance on the layout of lightning location websites and the need to improve the positioning accuracy,starting from the positioning principle,this paper analyzes the factors affecting the accuracy of lightning location,and studies the optimization methods of site layout and positioning algorithms.The main research contents and conclusions are as follows:1.Analyze and calculate the geometric dilution of precision(GDOP)distribution of the positioning accuracy index by changing parameters such as the layout of lightning detection stations,the height of lightning radiation sources,the distance between stations,the height and location of the main station,time,and site measurement errors.The results show that the Y-type layout should be given priority when arranging the exploration station,the height of the main and sub stations should be as close as possible,and the distance between stations should be appropriately increased.The main station should be located at the geometric center of the exploration station space.Provide theoretical guidance for the location of lightning location detection stations.2.Aiming at the problem that the site layout is constrained by geographical conditions during actual station layout,an optimized station layout method based on differential evolution algorithm and cuckoo search algorithm is proposed.Taking the station coordinates as the independent variables,the station location range as the constraint conditions,and the minimum average lightning location error in the target area as the criterion,the objective function for lightning location optimization is determined,and the lightning location optimization model is established.The simulation experiment shows that the average positioning error of the target area after the optimized layout of the cuckoo search algorithm is 0.432 km,which is reduced by 17.7% and 23.1% compared to the average positioning error of 0.525 km and 0.562 km under the traditional Y-type and T-type layout,respectively.When the main detection station is not fixed,the average error of the target area optimized by the cuckoo search algorithm decreases to 0.162 km.3.Aiming at the problem that the positioning accuracy of traditional positioning methods is greatly affected by gross data errors and station network layout,a positioning algorithm based on time difference and clustering algorithm is proposed.Based on the principle of time difference of arrival,lightning location data are combined and located.A k-means clustering algorithm is used to classify the combined location values and eliminate outliers to obtain the final location value.Taking the lightning detection network in Jiangsu Province as an example,the effects of regional positioning error distribution,timing accuracy,and station network layout on positioning error were quantitatively studied.The experimental results show that compared to the traditional arrival time difference method,the regional center positioning error calculated by this method is reduced from 5 km to 2 km;The root mean square error of four station positioning is reduced from 0.89 km to 0.07 km;The impact of timing errors on positioning errors has changed from a sharp increase to a slow increase,and the impact of station network layout on positioning errors has significantly decreased. |
