A Single Station Lightning Warning Equipment Based On The Principle Of Interferometer

The problem of lightning location can be solved by means of either multistation orsingle-station techniques. Multistation techniques are the most accurate, although the facilitiesare of complicated structure and very expensive.It is much more convenient to locate the sources from a single site. Sometimes it is the onlypossible way, e.g., for a system on board an aircraft or a vessel. Single-site lightning locationsystems usually combine a direction finder with a technique to estimate the distance of thesource. Accordingly, the present work includes two relatively independent parts which arepertinent to direction finding and distance finding, the latter is to be further improved.A new single-site distance finding method for lightning which based on the technique ofbroadband interferometers has been proposed. Vertical antenna array was set to get thephase-difference of lightning radiation signals, then the elevation of the arrival signal wasobtained. Both the distances of the cloud-to-ground and cloud flashes can be estimated from theelevation. The error analysis indicated that the overall uncertainty of the new method was lessthan25%in the range of50km, less than30%in the range of100km.Based on the new method, a Single-site Lightning Warning System has been developed,including the hardware and software. The software, which was compiled by NI LabView, couldcontrol the high-speed oscilloscope and GPS clock module synchronously. According to thethunderstorm distance and lightning frequency, the warning could be given by the system.The system has been used to detect the lightning during two thunderstorms in Chongqingon26July2011and27July2011. Thousands of lightning were recorded in the thunderstorm bythis system, whose lightning frequency distribution correspond with the multistation lightninglocation frequency well. The distance-finding result was matched to the multistation lightninglocation result by the time stamp. The comparison shows that the distance-finding error of morethan80%of lightning is less than20%, which proved the new method could detect the lightningin the range of100km and its measurement error was consistent with the error analysis.The research has provided a new method of single-site lighting warning, which achievedthe cloud flash observation unprecedentedly, has a strong practicability.