Statistical study of equatorial scintillations at Ancon, Peru

Abstract

The 136 MHz interferometric system at the past NASA Satellite Track­ing Station in Ancón, Perú, consists of two orthogonal baselines aligned along the North-South and East-West directions. A sizable number of interferometric records intended far operation­al tracking was spoiled by large amplitude and phase fluctuations. Ir - regularities In the ionosphere, those associated with the spread-F phenomena, are the cause of these fluctuations (scintillations). In most of the distorted records the North-South baseline inter­ferometer shows only a slight distort(on from the expected satellite graph whlle in the East-West interferometer the distortions are severe. This clearly shows the anisotropy of the irregularities and that they are elongated and aligned the magnetic field lines(Z) as have been found by other authors. The absence of North-South phase distortions when East­West distortions are present facilitates the detection of weak scintillations against the background noise. Far the purpose of this report the East-West baseline interferometric distortion was taken as an indication of scintillations.