Elongation of irregularities in ionospheric F-region over the magnetic equator in India

Abstract

The diffraction pattern of the field strengths of pulsed radio waves of frequency 4.7 Mc/s reflected from the F-region of the ionosphere near the magnetic equator in India are studied with the help of ten receiving aerials, six in the E-W and five in the N-S directions at distances of 60-480 m. The cross-correlation between the signal strengths at paired aerials along the N-S direction decreases very slowly with increasing separation, while along the E-W direction the correlation decreases very rapidly with increasing distance between the aerials. This suggests that the irregularities causing the fading of short radio waves near the magnetic equator are highly elongated along the N-S direction.