Diagnosis of the turbulent state of ionospheric plasma by propagation methods


  • K. C. Yeh,

  • C. H. Liu


An electromagnetic signal randomized by scattering from plasma irregularities and by subsequent diffraction in the nonrandom part of the medium is known to bear statistical information about the plasma turbulent irregularities. For example, if the turbulent spectrum is of the form κp in its wavenumber dependence, the received amplitude of the electromagnetic signal will fluctuate with a high frequency spectral asymptote of the form υ1−p. However, a power-law turbulent spectrum of the form κp has certain nonphysical difficulties if cutoffs at both the inner scale and the outer scale are not introduced. In addition, in this paper it is shown that the mean arrival time and the mean square pulse width are rather sensitive to values of the outer and inner scales of ionospheric turbulence. Information concerning the values of these scales is rather meager at present. It is therefore suggested that pulsed experiments be made so that the inner scale and the outer scale can be determined. Possibilities of making similar measurements on a laboratory plasma are also implied.