RADIO PHYSICS AND RADIO ASTRONOMY

PACS numbers: 94.20.wc, 94.20.de 

Purpose: A comparative analysis of the phase and frequency methods for determining the Earth-ionosphere effective waveguide heights for the basic and higher types of normal waves (modes) and distance to the source of radiation – lightning – has been made by analyzing pulse signals in the ELF-VLF range – tweek-atmospherics (tweeks).

Design/methodology/approach: To test the methods in computer simulations, the tweeks waveforms were synthesized for the Earth-ionosphere waveguide model with the exponential conductivity profile of the lower ionosphere. The calculations were made for a 20-40 dB signal/noise ratio.

Findings: The error of the frequency method of determining the effective height of the waveguide for different waveguide modes was less than 0.5 %. The error of the phase method for determining the effective height of the waveguide was less than 0.8 %. Errors in determining the distance to the lightning was less than 1 % for the phase method, and less than 5 % for the frequency method for the source ranges 1000-3000 km.

Conclusions: The analysis results have showed the accuracy of the frequency and phase methods being practically the same within distances of 1000-3000 km. For distances less than 1000 km, the phase method shows a more accurate evaluation of the range, so the combination of the two methods can be used to improve estimating the tweek’s propagation path parameters.

Key words: lightning location, diagnostics of the lower ionosphere, ELF-VLF radio waves, tweek-atmospherics

Manuscript submitted 12.10.2016

Radio phys. radio astron. 2016, 21(4): 270-278

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