Patent ID: 11960050
Assignee: NANJING JOINT INSTITUTE FOR ATMOSPHERIC SCIENCES
Field: Measurement (Instruments)
Classification: CPC G  Y | IPC G

Claim 5:
6. A fusion method of satellite-based and ground-based lightning data, comprising following steps:
step S1, selecting valid data in the satellite-based and ground-based lightning data: selecting group products of satellite-based lightning, and data of cloud-to-ground lightning return strokes as well as cloud flash pulses received by a ground-based VLF/LF three-dimensional lightning locator as valid data for fusing, wherein the data of the cloud-to-ground lightning return strokes and the cloud flash pulses received by the ground-based VLF/LF three-dimensional lightning locator comprise occurrence times, positions and lightning current intensities;
step S2, determining a time threshold for fusing the satellite-based and ground-based lightning data: determining a difference of longitudes and latitudes to 0.2°, within a range of 0.02 s to 2 s, changing time window values with a time resolution of the satellite-based lightning data as a progressive speed, and calculating a matching degree MP between the satellite-based lightning data and the ground-based lightning data under specified time and space windows, and taking a change inflection point of the matching degree MP as the time threshold, wherein the matching degree is obtained by a following formula:, M
    ⁢
    P
   
   =
   
    
     
      G
      S
     
     G
    
    ×
    1
    ⁢
    0
    ⁢
    0
    ⁢
    %
   
  
  ,
 

wherein the matching degree MP represents a ratio of a number of group products matched with at least one of the cloud-to-ground lightning return strokes or cloud flash pulses to a total number of the group products detected by the satellite-based lightning under the specified time and space window, and GS is the number of the group products matched with at least one of the cloud-to-ground lightning return strokes or the cloud flash pulses; G is the total number of the group products detected by the satellite-based lightning;
step S3, determining a spatial threshold for fusing the satellite-based and ground-based lightning data: selecting samples from an isolated thunderstorm system, and calculating centroid distances between lightning clusters detected by satellite-based and ground-based lightning detection systems in an evolution process of same the thunderstorm system, and taking a distance corresponding to an 80th percentile as the spatial threshold;
step S4, based on the time threshold and the spatial threshold determined in the step S2 and step S3 respectively, considering ground-based lightning data and satellite-based lightning data within the time threshold and the spatial threshold to be overlapped, eliminating the satellite-based lightning data overlapped, and merging remaining satellite-based lightning data with the ground-based lightning data to obtain a fused all lightning data set; and
step S5, applying the fused all lightning data set to provide lightning protection and disaster reduction business services.