Effect of Ionospheric Plasma Irregularities on Communication System Parameters

Abstract

The scintillation has been monitored at Rajkot using the VHF (250 MHz) signals from geostationary satellite FLEETSAT at 73°E since 1986. The paper describes the observed characteristics of scintillation such as its noctural occurrence pattern, seasonal, geomagnetic and solar activity dependence. Employing digital data acquisition and power spectral analysis techniques, quantitative parameters such as the scintillation index S₄, upper roll of frequency and spectral slope are derived and discussed in terms of the parameters of causative plasma irregularities. Spaced receiver technique and cross correlation analysis is employed to determined the characteristic scale size and velocity of the irregularities. A comprehensive study of the above parameters throws some light on the possible plasma instability mechanism responsible for the generation of those irregularities. The effects of the irregularities in terms of signal statistics such as cumulative amplitude distribution functions, fade rate, message reliability and bit error on a typical modern communication system are computed and presented.

Additional information

Notes on contributors

M N Jivani

Mahesh N Jivani obtained his MSc (Electronics) from Saurashtra University in the Year 1995 and joined as lecturer in the Dept of Electronics, Saurashtra University in 1999. He has been working for his PhD on Effects of ionospheric scintillation on communication system. His other interests i are in Data Communication, Intranet-Extranet. Wide Area Network and Computerized Information Technology.

H P Joshi

H P Joshi obtained MSc (Physics) and PhD (Space Physics) in 1982 and 1990 respectively. He has more than 12 years teaching experience both at UG and PG level. He has published several research Journals. At present he is lecturer in Electronics at Saurashtra University He has successfully completed a few research projects sponsored by ISRO.

K N Pathak

Kamlesh Pathak received his MSc (Physics) and PhD also in Physics from Saurashtra University in the years 1990 and 1995 respectively. He is currently lecturer at Sardar Vallabhbhai Regional College of Engineering and Technology at Surat. He has published five papers on his topic of research. His interests are in radio communication and ionospheric physics.

Boby Mathew

Boby Mathew received his MSc (Physics) from Kerala University and PhD in Physics from Saurashtra University in the years 1987 and 1992 respectively. He is currently lecturer at St Joseph's College at Bangalore. He has published six papers on his topic of research. His interests are in radio communication and ionospheric physics.

K N Iyer

Krishna Narayana Iyer obtained his MSc (Physics) from Kerala University in 1969 and PhD-(Space Physics) from the Physical Research Laboratory, Ahmedabad in 1976. He is a Professor leading the Space Physics Group at the Dept of Physics, Saurashtra University since 1987. He has guided 8 students for their PhD degree and has 80 publications to his credit. He has visited UK. Italy. Austria. Japan on research assignments and for attending conferences. He has successfully completed many research projects sponsored by Dept of Science & Technology, Department of Space etc on Ionospheric and atmospheric studies. He is elected a Fellow of Gujarat Science Academy in 1999 and is on the editorial board of Indian Journal of Radio & Space Physics.