ESTIMATES OF THE SCATTERING CROSS-SECTION OF EQUATORIAL ELECTROJET IRREGULARITIES OVER THE 3-MHZ TO 7-MHZ FREQUENCY BAND

E(sq) echo intensities recorded by a dynasonde system operated at Huan cayo, Peru, are used to estimate the scattering cross section of equat orial electrojet plasma irregularities in the 3 to 7 MHz frequency ban d. The scattering radar cross section of vertically propagating approx imately 20-m scale electrojet irregularities is estimated as approxima tely 3 x 10(-7) m-1 over a period exhibiting f(o)E values of 2.7 to 2. 9 MHz. The cross-section variation with Bragg wavenumber k is found to be characterized with a power law index of approximately -3 over the HF band.