Lightning Location Algorithm Based on DBSCAN and Grid Search

Lightning location system can monitor the time and location of lightning in real time, supporting disaster early warning and post-disaster treatment in meteorology, power, aerospace, forest fire prevention and other fields. The location algorithm directly affects the accuracy of lightning detection results. Traditional location algorithms may often fall into the local optimum and needs a large amount of calculation. The practical application is limited by the computer capability and the anti-error interference ability is poor. A new lightning location algorithm DG-LLA (DBSCAN and Grid-Search Lighting Location Algorithm) is proposed. The algorithm is verified by a lightning accident example and regional simulation, and then by locating historical data detected in the national lightning monitoring network. The performance of the new algorithm is compared and further analyzed from three aspects:Lightning frequency temporal distribution, lightning spatial distribution and regional spatial distribution.Simulation results of lightning example show that the location error of TDOA (time difference of arrival) method is the largest, reaching 1314 m. Taylor series expansion method is a classical iterative algorithm with an error of 881 m. The error of proposed DG-LLA algorithm is significantly reduced to 84 m. Examples of artificial lightning initiation show that the new algorithm DG-LLA is more accurate than the national lightning monitoring network, and the average location error is 32.2% lower than operational network. Lightning location algorithm based on adaptive DBSCAN and grid-search optimization can effectively identify noise data and enhance the ability of anti-error interference. Regional simulation result shows that TDOA method and Taylor series expansion method have large positioning errors, with the RMSE (root mean square error) of 982 m and 668 m, respectively. When DBSCAN is added to location, the RMSE is significantly reduced to 406 m. After DBSCAN and grid search are added, the RMSE is further reduced to 349 m. Lightning location algorithm based on adaptive DBSCAN and grid search optimization improves the local searching ability and global searching ability of space and overcomes shortcomings of traditional iterative algorithm, such as easy divergence and local optimum of optimization algorithm, and solve the lightning strike point stably and accurately, and it performances better than operational network. The utilization rate of return data increases from 43.4% to 51.5%. The radar echo around new locations has stronger characteristics and higher locating accuracy. It provides a new method for lightning location.