Dependence of the Drift and Anisotropy Parameters of the Ground Diffraction Pattern at the Equator on the E-W and N-S Extent of the Antenna Separation

Abstract

Simultaneous observations of the ionospheric drift and anisotropy parameters of the ground diffraction pattern at Thumba (0.6°S dip) using the spaced receiver technique were conducted at two adjacent receiving aerial systems of different sizes. It is shown that though the apparent drift speed Va shows very little dependence on the size of the triangle, the true drift speed V increases to some extent with the increasing E-W separation of the receiving aerials. The random drift speed Vc shows slight decrease with increasing E-W separation while the true and apparent drift directions φ and φa show almost no dependence. The axial ratio ‘r’ of the characteristic ellipse shows a positive dependence on the N-S separation of the aerials while the transverse size ‘b’ shows a small increase with the E-W separation. The orientation of the characteristic ellipse φ tends to be more close to magnetic N-S with increasing N-S separation of receiver aerials.