Radar reflectivity of lightning-induced plasmas

✍ Scribed by M.C. Lee; Y.R. Dalkir; E.R. Williams

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 314 KB
• Volume: 60
• Category: Article
• ISSN: 1364-6826
• DOI: 10.1016/s1364-6826(98)00024-8

✦ Synopsis

The scattering of radio waves from lightning!induced plasmas is investigated[ The plasmas are modeled as long\ perfectly conducting cylinders with surface density irregularities on a scale much smaller than the total channel length[ The theoretical wavelength dependence of the radar re~ectivity is compared with experimental results obtained with the MIT C!band and S!band radars[ It is found that the theory of rough surface scattering predicts two types of inverse power law wavelength dependence for radar re~ectivity[ They are 0:l and 0:l 1 \ which correspond to density ~uctuations of lightning plasmas with a Gaussian type spectrum and a power!law type spectrum\ respectively[ By contrast\ the theory of long\ thin conductors predicts a wavelength dependence of l 9[4 for radar re~ectivity[ The experimental observations on common lightning targets free of precipitation masking e}ects show a mean wavelength dependence of 0:l 9[73 [ The observed wavelength dependence lies between the predictions of the two theories[ It indicates that the wavelength dependence in these observations is bounded by these two theories[ We conclude that the proposed theory for fat overdense plasma channels with irregular surfaces and the theory for long\ thin overdense channels bracket the observed wavelength dependence[ Þ 0887 Elsevier Science Ltd[ All rights reserved[