Phase and amplitude perturbations on subionospheric signals explained in terms of echoes from lightning-induced electron precipitation ionization patches
Phase and amplitude perturbations on subionospheric signals explained in terms of echoes from lightning-induced electron precipitation ionization patches
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用闪电引起的电子沉淀电离斑块的回波解释亚电离层信号的相位和幅度扰动
DOI：
10.1029/ja093ia10p11543
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发表时间：
1988
影响因子：
--
通讯作者：
C. Adams
中科院分区：
文献类型：
--
作者：
R. Dowden;C. Adams
在地球-电离层波导中传输的甚低频信号的相位和幅度扰动(TRIMPI)通常被解释为沿大圆路径的降水诱导的修改，就好像它是一维(1-D)波导一样。这里提出的另一种2-D观点是，降水诱导的电离斑块从大圆路径横向移动，在接收器产生相对于直接信号略有延迟的回波。直接信号和回波信号之间的干扰会产生两个符号的相位和幅度调整。这里假定为单模传播，因为第二模的幅度很可能比第一模的幅度高出∼12分贝。我们将这一理论应用于1987年7月10日在西北角(NWC)-达尼丁路径上观测到的一系列TRIMPI。这表明降水区的南北漂移与哨声导管的漂移速度一致。这一理论也适用于文献中发表的事件。
Phase and amplitude perturbations (trimpis) on VLF signals propagating in the earth-ionosphere waveguide are usually explained in terms of precipitation-induced modification along the great circle path as though it were a one-dimensional (1-D) waveguide. The alternative 2-D view presented here is that precipitation-induced ionization patches, laterally displaced from the great circle path, produce echoes at the receiver slightly delayed relative to the direct signal. Interference between the direct and echo signals can produce both phase and amplitude trimpis of both signs. Single-mode propagation is assumed here, since it is likely that the second mode amplitude exceeded that of the first by ∼12 dB. We apply this theory to a sequence of trimpis observed on the North West Cape (NWC)-Dunedin path on July 10, 1987. This indicates a north–south drift of the precipitation region consistent with drift speeds of whistler ducts. The theory is also applied to events published in the literature.