Houston LDAR II Network: Performance Analysis

The Houston Lightning Detection and Ranging (LDAR) network, a VHF total lightning detection system, began operation in mid-August 2005. The Houston LDAR network is an array of twelve VHF time-of-arrival (TOA) sensors spaced roughly 25 kilometers across the Houston metropolitan area that detect short impulses of VHF radiation (LDAR sources) emitted during the lightning breakdown process. The network was established to examine the total lightning structure of thunderstorms and conduct detailed studies of the effects of a large metropolitan region on thunderstorm electrification. In addition to scientific research, the Houston LDAR II network provides realtime lightning information to the Johnson Space Center, the Houston National Weather Service office, various local school districts, and airports. Both uses require an understanding of LDAR data and its limitations. Three network performance metrics that are essential to determine are the network range, the LDAR source location accuracy, and the effective network detection efficiency. Preliminary analysis of a Mesoscale Convective System (MCS) on October 31, 2005 that traversed the Houston LDAR II network coverage area indicated a usable network range of approximately 135 kilometers and a maximum detectable range near 225 kilometers. Using LDAR data from several events, the network performance metrics will be analyzed and presented.