A System for Recording Phase Path Variations of Ionospheric Reflections

Abstract

An experimental set-up developed for continuous recording of the phase path variations of reflections at normal incidence from discrete regions of the terrestrial ionosphere is described. Salient features of the system design and hardware implementation of the same are presented. The phase path sounder, which is currently operated on a probing frequency of 5.0 MHz at the Kodaikanal Observatory, comprises of a broadband transmitter, phase coherent receiver(s), frequency synthesiser, timing and logic circuits and analog recording facilities. Typical features of the phase path variations of reflections from ionospheric F-region over Kodaikanal derived from recent data runs are discussed and the resourcefulness of the system for diagnostic studies of the equatorial ionosphere is outlined