A PARAMETRIC METHOD OF SITE ERROR ESTIMATION FOR A LIGHTNING LOCATION SYSTEM

In this paper,a parametric method of site error estimation is developed for a lightning location system (LLS) which consists of three or more direction finders (DFs) and one position analyzer (PA).The site error for each DF is a function of bearings measured by the DF,and is assumed to be limited-term harmonics.The problem of site error estimation is reduced to a non-linear unconstrained minimization problem by employing the eigen technique (Orville Jr.,1987).The site error can be found directly by minimizing the objective function.By using the data set obtained with the LLS of three DFs in Beijing area during the summer of 1988,the site error correction curves for all DFs were found.About 4900 lightning flashes detected by the three DFs were used.The results showed that about 95% of the flash residuals of the sample were within ±1 degree after corrections.The lightning locations with site error corrections were more consistent with the corresponding radar echoes than those without corrections.