Department of Physics.
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Item Effects of Aerosol Scattering Attenuation on Free-Space Optical Link Performance in Owerri, Southeast, Nigeria(Science and Technology: Developments and Applications Vol. 8,, 2025) Akinwumi, A.; Ayo-Akanbi, O.; Omotosho, T. V; Arijaje, T; Ometan, T.; Adewusi, O.High-speed, point-to-point data transmission through laser beams across terrestrial networks is sometimes referred to as "Free-Space Optics" (FSO). Multimedia applications including social networks, OTT platforms, video conferencing, and multimedia streaming are driving up the demand for data rates and channel bandwidth, which has led to a telecommunications bottleneck. In spite of the several benefits of using free-space optical (FSO) communication systems as complementary platforms for next-generation networks, the existence of atmospheric disturbances such as fog and scintillations are key sources of signal impairment that affect system performance. Thus, it is crucial to learn about the specific weather patterns of the areas where FSO lines will be installed. The purpose of this work is to estimate the availability performance of FSO lines broadcasting at both 850 nm and 1550 nm by performing a statistical analysis of meteorological visibility data gathered for Owerri in Nigeria over a 21-year period (2000-2021). The results show that the visibility during the most common fog events in Owerri is 100 meters. The probabilities of encountering and exceeding the scattering attenuations associated with Owerri's most common fog event are 0.0002 and 0.0229, respectively. This research could be expanded in the future by exploring the effects of varying localized climatic conditions on the many forms of optical signals, such as plane, spherical, and Gaussian beam waves. This would aid in the modelling of different forms of attenuation for deployment sites of FSO or hybrid FSO systems.Item Modelling and Prediction of Satellite Signal Path Loss using the ARIMA models at Ku-band in Lagos State, South Western Nigeria(ICSSD 2024 (IOP Conf. Series: Earth and Environmental Science), 2025) Arijaje, T. E.; Omotosho, T. V; Aizebeokhai, A. P.; Akinwumi S. A.; Oyeyemi, K. D.Satellite signal path loss is the reduction of signal strength between the transmitting satellite and the receiving antennas on the earth surface. It is cause by effects such as reflection, free space loss, diffraction, refraction and absorption. It is also cause as a results of the environment, terrain contours, medium of propagation, height of antennas location and transmitting distance between the transmitter and receiver. Several methods such as the traditional methods and machine learning techniques have been explored. However, statistical method of path loss prediction has been completely utilized. In this work, prediction of path loss using the autoregressive integrated moving average (ARIMA) technique was considered. Four different ARIMA models at Ku-band were explored using eight years in Lagos State. The method consists of some steps in the run time analysis: the first stage involved identifying the ARIMA model by creating an Autocorrelation Function (ACF) and Partial Autocorrelation Function (PACF) plots and checking if the data are stationary. The second stage involved estimating the ARIMA model, which consists in testing the parameters' significance after obtaining the model's parameters. The ARIMA model is adopted if the parameters are significant. The third stage involved diagnostic checking, in which a test was carried out to see if the adopted model was statistically significant. The fourth stage involves predicting the path loss after the diagnostic process using the adopted or selected ARIMA model. From the analysis, it can be concluded that the best ARIMA model for path loss prediction in Lagos at Ku-band is ARIMA (1,0,0). The ARIMA (1,0,0) model is a better path loss prediction model than the other ARIMA models, indicating that the model parameters are significant at 0.05 with the slightest MSE error, thereby meeting the test of independence. Therefore, for sitting and planning of radio signal propagation technologies in the study location, policy-makers and engineers in telecommunication industry in Nigeria can take advantage of the results within the area of study towards sustainable tele-communication and infrastructure (SDG goal 9).