Comparison of hourly variations of radio refractivity for quiet and disturbed days during dry and rainy seasons at Minna

Okoro, O. N.; Agbo, G. A.; Ekpe, J. E.; Obiekezie, T. N.

doi:10.14419/ijbas.v2i1.541

Cited by 5 publications

(6 citation statements)

References 7 publications

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“…Transmission of a radio signal in the lower atmosphere is affected by many processes which include variations in air temperature, pressure, and humidity. These variations in weather parameters often result in refractivity changes [9] . These changes can result in abrupt changes in the propagation direction of a radio signal resulting in signal loss.…”

Section: Review Of Related Workmentioning

confidence: 99%

The Refractive Effect of k-Factor on Radio Propagation over Lokoja, Nigeria

Akinbolati¹,

Ikechiamaka²,

Isaiah³

2023

j. of electron. & inf. syst.

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The effective earth radius factor (k-factor) has a refractive propagation effect on transmitted radio signals thus making its study necessary for the proper planning of terrestrial radio links and power budget. This study was carried out over the city of Lokoja, Nigeria, using ten years (2011 to 2020) atmospheric data of temperature, pressure and humidity both at the surface (12 m) and at 100 m AGL. The data were retrieved from European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5. The k-factor yearly variation follows the same trend with minimum and maximum values obtained during dry and wet season months respectively. In addition, the highest mean value of 1.00042 was recorded in the month of August while the lowest value of 1.00040 was recorded in the month of January with an overall mean value of 1.0003. This value is less than the recommended standard of 1.33 by ITU-R. The propagation effect corresponding to k < 1.33 is sub-refractive. The implication of this on radio wave propagation, especially terrestrial communications is that transmitted wireless signal is prone to losses. This can be mitigated through an effective power budget: Choice of transmitting antenna’s height and gain, so as to improve the Quality of Service over the study area.

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Section: Review Of Related Workmentioning

confidence: 99%

The Refractive Effect of k-Factor on Radio Propagation over Lokoja, Nigeria

Akinbolati¹,

Ikechiamaka²,

Isaiah³

2023

j. of electron. & inf. syst.

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“…ITU-R refractivity equations were used to calculate the surface radio refractivity values corresponding to the data collecting places based on collected meteorological conditions, as shown in (15)(16)(17)(18)(19)(20). Path losses of the signal along various routes will be calculated using (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). MATLAB software was used to analyse the gathered data for the transmitting base station during the dry and wet seasons.…”

Section: Modelling Of Path Loss Prediction For Dttv Communication Linkmentioning

confidence: 99%

Investigation and Modelling of Path Losses associated with Digital Terrestrial Television Communication Link Within the UHF band in Nigeria

Amusa,

Ilori,

Adejumobi

et al. 2023

Preprint

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The transition from analogue to digital television broadcasting (DTTV) ushered in a new age in worldwide TV culture. The migration necessitates a few technical studies, including path-loss prediction for DTTV communication lines. The purpose of this article is to predict path-loss on DTTV communication links inside UHF bands in Abeokuta, Nigeria, with Ogun State Television as the broadcasting station. Eight receiving sites, two kilometres apart, were chosen along the transmitter's contour. For pathloss prediction related with communication lines at those receiving sites, three empirical path-loss models (ECC-33, Hata, and Okumura) were applied. For a period of twelve months, actual measurements of received signal strength (RSS) and meteorological data (temperature, water vapour pressure, and atmospheric pressure) were taken at seven distinct times of day (0800, 1000, 1200, 1400, 1600, 1800, and 2000 hours). The measured RSS values and metrological data were used to calculate the real path-loss and surface radio refractivity of each receiving site, respectively. The gathered data were divided into dry and wet seasons, and separate models (Mwet-NO and Mdry-NO) for path-loss estimation were developed using multiple regression analysis. Metrics used for model evaluation were Root Mean Square Error (RMSE), Coefficient of Correlation, Coefficient of Multiple Regression, Mean Absolute Error and Mean Pathloss. Results shows that only Okumura model was close to actual path-loss obtained from measurements, indicating that both Hata and COST-231 models were un-suitable, further analysis revealed that Mwet-NO and Mdry-NO; compare well with the actual path-loss, hence, suitable for pathloss prediction in the study area.

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“…εr and μ=μ0 . μr, are the permittivity and permeability in F/m and H/m respectively, and εᵣ and μᵣ are the relative permittivity and permeability of the medium [6], [11].…”

Section: The Relative Refractive Indexmentioning

confidence: 99%

“…There are various models for conversion of (τ-min) into (1-min) rainfall statistics (see e.g. [5], [9], [10], [14]), usually based on either equal rainfall rate or equal probability approach; an example of the latter (as in [9]) results in a relationship of the form R1 min = a (Rτ min) b (6) where Rτ min is rain rate value measured in τ minutes τ≥1min) and R1 min the "one-minute" rain rate value, while a and b are appropriate regression coefficients. The difficulty with such techniques is that they usually require 1-min measured data to estimate the regression coefficients, which consequently are location-specific.…”

Section: _______________________________________________mentioning

confidence: 99%

Maximum Rain-Rate Evaluations in Aegean Archipelagos Hellas for Rain Attenuation Modeling at Microwave Frequencies

et al. 2016

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By utilizing meteorological data such as relative humidity, temperature, pressure, rain rate and precipitation duration at eight (8) stations in Aegean Archipelagos from six recent years (2007 -2012), the effect of the weather on Electromagnetic wave propagation is studied. The EM wave propagation characteristics depend on atmospheric refractivity and consequently on Rain-Rate which vary in time and space randomly. Therefore the statistics of radio refractivity, Rain-Rate and related propagation effects are of main interest. This work investigates the maximum value of rain rate in monthly rainfall records, for a 5 min interval comparing it with different values of integration time as well as different percentages of time. The main goal is to determine the attenuation level for microwave links based on local rainfall data for various sites in Greece (L-zone), namely Aegean Archipelagos, with a view on improved accuracy as compared with more generic zone data available. A measurement of rain attenuation for a link in the S-band has been carried out and the data compared with prediction based on the standard ITU-R method.

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Comparison of hourly variations of radio refractivity for quiet and disturbed days during dry and rainy seasons at Minna

Cited by 5 publications

References 7 publications

The Refractive Effect of k-Factor on Radio Propagation over Lokoja, Nigeria

The Refractive Effect of k-Factor on Radio Propagation over Lokoja, Nigeria

Investigation and Modelling of Path Losses associated with Digital Terrestrial Television Communication Link Within the UHF band in Nigeria

Maximum Rain-Rate Evaluations in Aegean Archipelagos Hellas for Rain Attenuation Modeling at Microwave Frequencies

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