GROUND-WAVE RECEPTION AND GROUND CONDUCTIVITY
GROUND-WAVE RECEPTION AND GROUND CONDUCTIVITY
No Thumbnail Available
Date
2015-03-06
Authors
EZEADUBU, O.N.D.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This investigative research consists of three parts:
Plotting of theoretical propagation curves with the aid of
computer, determining the effect of the variation of the
ground conductivity on ground-wave field strength and
deduction of the ground conductivity.
Theoretical ground-wave propagation curves were plotted
for flat earth with the aid of a digital computer for some
broadcast frequencies in use in the Northern States of Nigeria,
Computer CALCOMP programmes were developed for the plots.
The effect of the variation of the ground conductivity on
ground-wave field strength was investigated by measuring the
field strength radiated from MW radio stations for five months,
March - July, 1981. The measurements showed that the radiated
field strength was practically constant irrespective of
whether it was rainy or dry season. One of the conclusions
from the measurements was that as the variation of the ground
conductivity and vegetation have opposite effect on ground wave
the effective influence of the variation of ground conductivity
could be so small that it could not be detected with the field
strength meter. The field strength increases with increase
in the ground conductivity while vegetation attenuates
ground wave.
The determination of the ground conductivity in the
northern parts of Nigeria was carried out by the attenuation
technique. The ground resistivity method was used in
Samaru - Zaria to confirm the result obtained there by the
attenuation technique. According to the research results,
2, 3» and 4 mmho/m were obtained as the ground conductivities
in parts of Kaduna State; 3 mmho/m was obtained in Kano State;
2 mmho/m was the value obtained in Niger State. 3 and 4 mmho/m
were obtained in Sokoto State. A CALCOMP programme was used
in plotting the measured field strength on the theoretical
propagation curves.
All the CALCOMP programmes used in this research can be
found in the Users' Manual of the CALCOMP Programmes for
Plotting Theoretical Ground-Wave Propagation Curves written
by the author.
Description
A thesis submitted to the Postgraduate School,
Ahmadu Bello University, Zaria in partial
fulfilment of the requirements for the degree of
Master of Science in Electronics and Telecommunications.
Department of Electrical Engineering
Faculty of Engineering
Ahmadu Bello University
Keywords
GROUND-WAVE,, RECEPTION,, CONDUCTIVITY