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Modeling of Cloud Attenuation on Earth - Space Path in Ota Southwest Nigeria

Adewusi, M. O. and Omotosho, T. V. and Akinyemi, M. L. and Emetere, Moses and Akinwumi, S. A. and Ometan, Oluwafunmilayo O. (2019) Modeling of Cloud Attenuation on Earth - Space Path in Ota Southwest Nigeria. In: 6th International Conference on Space Science and Communication , 28-30 July 2019 , Johor Bahru, Malaysia, Malaysia.

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Abstract

A new cloud attenuation model on earth-space path has been develop for a tropical station (6.7°N, 3.23°E) based on cloud cover, radiometric measurement and climatological data at the Covenant University in Ota. The collection of station data by a 7GHz spectrum analyzer for the total attenuation at elevation angle of 59.9° to Astra 2 satellites located at longitude 28.2°E. Automatic weather station parameters and daily visual clouds observation; as well as the acquisition of station radiosonde data were carried out. The station spectrum analyzer data between 2014 and 2017 were analyzed to obtain cloud attenuation contributions from the total attenuation measurement. The measured Cloud attenuation was compared with eight existing cloud attenuation models. Cloud attenuation at 12.245 GHz is 3.40 dB compare to 0.81 dB cloud attenuation predicted by ITU-RP 840 model, next is the Liebe's model, followed by Slobin model. A new developmental model was derived for the tropical station. The new cloud attenuation model was developed using the station radiosonde data from 1953-2011 for the computations of each cloud layer's liquid water content and specific attenuation coefficient. The cumulative distribution curves obtained was compared with each simulation distribution and the closest match to the station measured cumulative distribution is considered in the new cloud attenuation model for the station. The new model predicted 4.0 dB margins for clouds attenuation at 0.01% unavailability for the station. The study reveal cloud attenuation was under estimate by the eight existing cloud attenuation model for the tropical station.

Item Type: Conference or Workshop Item (Paper)
Subjects: Q Science > QC Physics
Divisions: Faculty of Engineering, Science and Mathematics > School of Physics
Depositing User: Mrs Patricia Nwokealisi
Date Deposited: 27 Feb 2020 09:54
Last Modified: 27 Feb 2020 09:54
URI: http://eprints.covenantuniversity.edu.ng/id/eprint/13139

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