HR: 13:57h
AN: AE43A-02    [Abstracts]
TI: Recent Comparisons of VHF Lightning Mapping Using Interferometry and Time-of-Arrival Techniques
AU: * Lojou, J
EM: Jean-Yves.lojou@vaisala.com
AF: Vaisala, Inc., 2705 E. Median Rd., Tucson, AZ 85706 United States
AU: Cummins, K L
EM: Ken.Cummins@vaisala.com
AF: Vaisala, Inc., 2705 E. Median Rd., Tucson, AZ 85706 United States
AU: Cummins, K L
EM: Ken.Cummins@vaisala.com
AF: Dept. of Atmospheric Sciences, University of Arizona P.O. Box 210081, Rm. 542 1118 E. 4th Street , Tucson, AZ 85721 United States
AB: As part of Vaisala's technology and applications test bed in the Dallas-Fort Worth area in Texas, we have been operating two overlapping Total Lightning detection networks. One network employs VHF Interferometry (both 2- and 3-timensional instrumentation) and the other employs VHF 3-dimensional Time-Of-Arrival (TOA) techniques. For the first time, these two technologies can be compared and contrasted in a common region where they both exhibit good performance. The aim of the work presented is to evaluate the spatial and temporal "description" of lightning flashes provided by these two techniques, and to compare and contrast the relative strengths of these two approaches for Total Lightning mapping. This study employs data acquired during the summer of 2005. The analysis set includes data obtained by these two networks, as well as cloud-to-ground location data from the U.S. National Lightning Detection Network (NLDN). The spatial extent and vertical profile of sources from individual in-cloud and cloud-to-ground flashes are compared for various storm conditions, with both technologies clearly contributing supplemental information not provided by the other. Leader propagation velocities show a substantially unimodal distribution centered at about 10⁵ m/s for TOA-derived sources, whereas the velocity distribution for sources detected using interferometry exhibit a bimodal distribution with the second mode at about 10⁷ m/s. The most-probable interval-between-sources for TOA-derived sources seems to be a few milliseconds, whereas interferometry produces large populations with intervals near 100 microseconds and 100 milliseconds.
DE: 0694 Instruments and techniques
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: Fall Meeting 2005