Diffraction of 140 MHz ATS-6 Signal by Lenslike Ionospheric Irregularities

Abstract

Using the theoretical modelling of diffraction patterns produced by isolated ionospheric irregularities at E-region height, the scale sizes and maximum electron density enhancements are determined for the events observed at Delhi (lat., 28.6° N; long., 77.2°E) on 140 MHz radio beacon transmission from ATS-6 geostationary satellite. Some model calculations are done to see the effect of scale size and electron density on the characteristics of observed diffraction pattern. Simulation of some of the events observed on 140 MHz radio beacon transmission by isolated ionospheric irregularities at the E-region heights suggests that these are produced by the one dimensional Gaussian fluctuations in electron density. The scale sizes and maximum electron density enhancements of the isolated irregularities determined are found to vary from 30 to 300 m and 4.3 x 10¹¹ to 1.4 X 10¹² eI./m³, respectively. The results are compared with those of other workers.