THE EFFECTS OF EQUIVALENT THICKNESS AND DRIFT VELOCITY ON SCINTILLATION POWER SPECTUM IN IONOSPHERIC IRREGULAR STRUCTURE

By use of the Fourier power expression of scintillation intensity of thin phase screen with limited thickness L, which is derived from principle theory of diffraction, the effects of the equivalent thickness L and the drift velocity V on the Fourier power spectum are studied. The results show that, as L increases, the Fresnel oscillation amplitude decreases and the Fresnel radius remains unchanged; as V increrases, the Fresnel oscillation amplitude remains unchanged and tEe Fresnel radius increases. The ratio of sequent frequences corresponding to the minimum values of poker is 1:2:3:.:n, not √2:√3:…:√n this is in good agreement with the observationa .data. Comparing the computer comulation results of power spectum wih observational data, both the,values of equivalent thickness and me drift velocity of real ionospheric irregular structure are obtained.