| Summary: | 碩士 === 國立中央大學 === 太空科學研究所 === 106 === The Chung-Li VHF Radar Station set up an interferometric antenna array in the Republic of China in 2012. This paper uses this array for lightning observation. Due to the high electron concentration characteristics of the lightning channel, it reflects the electromagnetic waves emitted by the transmitter. The wave path difference of the echo arriving at each receiving antenna will be different due to the cross-shaped arrangement, so that the coordinate parameter of the lightening channel in the three-dimensional space can be obtained, and then the lightning structure in the three-dimensional space can be known.
The Bureau of Meteorology uses the Time Of Arrival (TOA) method to locate lightning. In the past, when the TOA method was used to locate the location, only the GPS timing error was considered. However, there are actually many factors that affect the error. Therefore, a new model, which considers all error terms needs to be established.
The purpose of this experiment is to compare the locating data of the Bureau of Meteorology with the locating data of Cung-Li VHF radar, hoping to achieve the effect of verifying the locating error of the Bureau of Meteorology. However, there is still a certain gap between the comparison results of the two systems and the simulation results. If one considers the difference in the lightning detection mechanism, the criteria for both systems observing the same lightning will be redefined and the time criteria will be relaxed to 0.3 seconds (lightning event duration). After redefining the criteria, the distance difference between the two systems has a reasonable gap with the error simulation results.
Using the new error simulation model to analyze the locating accuracy of different sets of lightning location systems, and to analyze the current site of the Bureau of Meteorology, it was found that there was an uneven distribution in the western part of Taiwan and eastern Taiwan. After the simulation, it was found that adding Hualien, Taitung Station will have a better locating accuracy.
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