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ABSTRACT
Concern regarding lightning activity as a precursor of severe weather is increasing. Atmospheric electricity, including lightning phenomena, is one of most serious threats to successful space launch operations. The objective of this study was to evaluate the performance of two different lightning detection networks using a time-range correlation method. Understanding lightning detection network performance enables the weather forecaster to support decisions made regarding space launch operations. The relative detection efficiency (ReDE), observation ratio, ellipse area for 50% probability of location, number of sensors reporting (NSR), time difference, and distance, as parameters that predict system performance, were calculated with the time-range correlation method using cloud-to-ground (CG) flash data from the Korea Aerospace Research Institute Total Lightning Detection System (KARITLDS) and from the Korean Meteorology Administration Lightning Detection Network (KLDN). In this study, 15 thunderstorms were selected from 2008-09 data. A total of 41 192 and 28 976 CG flashes were recorded by KARITLDS and KLDN, respectively. In all, 19 044 CG flashes were correlated as being the same flash. The observation ratios, ReDE^sub KARITLDS^, and ReDE^sub KLDN^ were calculated as 1.42, 0.66, and 0.46, respectively. Eighty percent of CG flashes detected by the KARITLDS (KLDN) had elliptical areas less than 5 km^sup 2^ (12 km^sup 2^), where the elliptical areas were defined as having a 50% probability of containing the CG flash. Two regions showing a high observation ratio were due to high KARITLDS detection efficiency and to the blocking of electromagnetic wave propagation by Mount Hanla at 1950 m above sea level.
1. Introduction
Natural and triggered lightning poses a significant threat to space launch vehicles, launch complexes, and ground range tracking systems at space centers. As of 1 March 2004, a total of 13 of 162 Ariane 4 and 5launch operations at the Centre Spatial Guyanais had to be postponed because of weather conditions (Isabelle 2004). For the Eastern Range at Cape Canaveral and the National Aeronautics and Space Administration (NASA) Space center, a total of 4.7% of the launches from 1 October 1988 to 1 September 1997 were scrubbed and 35%were delayed because of Lightning Commit Criteria (LCC; M. W. Maier 1999, unpublished manuscript). The cost impact of launch operation scrubbing varies from 150 000 U.S. dollars (USD) to over 1...