An FDTD Study of Errors in Magnetic Direction Finding of Lightning Due to the Presence of Conducting Structure Near the Field Measuring Station

Abstract

Lightning electromagnetic fields in the presence of conducting (grounded) structure having a height of 60 m and a square cross-section of 40 mˆ40 m within about 100 m of the observation point are analyzed using the 3D finite-difference time-domain (FDTD) method. Influence of the conducting structure on the two orthogonal components of magnetic field is analyzed, and resultant errors in the estimated lightning azimuth are evaluated. Influences of ground conductivity and lightning current waveshape parameters are also examined. When the azimuth vector passes through the center of conducting structure diagonally (e.g., azimuth angle is 45˝) or parallel to its walls (e.g., azimuth angle is 0˝), the presence of conducting structure equally influences H x and H y , so that H x /H y is the same as in the absence of structure. Therefore, no azimuth error occurs in those configurations. When the conducting structure is not located on the azimuth vector, the structure influences H x and H y differently, with the resultant direction finding error being greater when the structure is located closer to the observation point.

Finite-difference time-domain analysis of ELF radio wave propagation in the spherical Earth–ionosphere waveguide and its validation based on analytical solutions

“…When a small part of the Earth-ionosphere cavity needs to be analyzed, a local volume can be divided into FDTD grid in 2D cylindrical (Cummer, 2000;Hu and Cummer, 2006;Marshall, 2012;Qin et al, 2019), or 3D Cartesian coordinate systems (Araki et al, 2018;Suzuki et al, 2016). It facilitates taking into account some complex inhomogeneities and ionospheric anisotropy in the analysis of ELF-VLF radio waves.…”

FDTD analysis of ELF radio wave propagation in the spherical Earth-ionosphere waveguide and its validation based on analytical solutions

“…When a small part of the Earth-ionosphere cavity needs to be analyzed, a local volume can be divided into FDTD grid in 2D cylindrical (Cummer, 2000;Hu and Cummer, 2006;Qin et al, 2019), or 3D Cartesian coordinate systems (Araki et al, 2018;Suzuki et al, 2016). It facilitates taking into account some complex inhomogeneities and ionospheric anisotropy in the analysis of ELF/VLF radio waves.…”

Detection performance analysis of advanced direction time lightning detection system in China

“…Multiple factors, including sensors, data acquisition methods, return waveform recognition, positioning algorithm, etc. can affect the detection performance of lightning location network (Bennett et al, 2011;Nag et al, 2015;Suzuki et al, 2016;Li et al, 2022), and it is difficult to evaluate each factor one by one. Chen et al (Chen et al, 2013) proposed to use historical records of the lightning location data to evaluate the DE of lightning location network, and applied the method to the lightning location network in Yunnan Province.…”