One-Minute Rain-Rate Contour Maps for Microwave-Communication-System Planning in a Tropical Country: Nigeria

Ojo, J. S.; Ajewole, M. O.; Emiliani, Luis

doi:10.1109/map.2009.5432046

Cited by 33 publications

(33 citation statements)

References 12 publications

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“…Earlier studies have presented useful tools for planning satellite and terrestrial microwave links over Nigeria [12,13], the one-minute rain rate estimates presented were deduced mainly from satellite data. Interestingly, a recent comparison by Ojo and Omotosho in [14] however reveals that one-minute rain rate estimates derived from ground data generally performs better than those obtained from satellite data.…”

Section: Introductionmentioning

confidence: 99%

“…Prominent among others are those developed from data collected in Brazzaville, Congo [15], those developed from a data bank containing 290 data sets for 30 countries [16], those predicting rain rain rate based on local climatological data available over any location [17], and the global ITU-R rain rate model as recommended in [18]. These models have been useful for the prediction of the cumulative rain rate distribution for selected locations in Nigeria [13,[19][20][21]. The radio climatological data required to ascertain their suitability for predictions over Nigeria is still sparse.…”

Section: Introductionmentioning

confidence: 99%

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Recent Update on One-Minute Rainfall Rate Measurements for Microwave Applications in Nigeria

Obiyemi

Adetan²,

Tunji³

2015

WCMC

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Abstract:Rain rate statistics is required for planning both satellite and terrestrial links, especially in the microwave and millimeter wave bands. Presented in this work is the one-minute rain rate statistics observed over seventeen months using an electronic weather station -Davis Vantage Vue. The installation is at the main campus of Osun State University, Osogbo (7° 76' N, 4° 60' E), Nigeria. The cumulative rain rate distribution from the measured rain rate is presented alongside predictions by other prominent models. The R 0.01 estimate as high as ~ 120 mm/h was obtained from the surface data and subsequently employed in estimating the fade margin over a hypothetical DTH link for the reception of digital television content at 12.245 GHz from EUTELSAT W4/W7. Estimates presented over time percentages ranging between 0.001% and 1% are dissimilar. However, their suitability for predicting fade margins over this location could be ascertained via a performance analysis, based on experimental attenuation estimates over the link. The first point rain rate estimate from surface data over Osogbo is reported here and will be very useful for modeling rain attenuation and for planning both terrestrial and earth-space microwave links.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Recent Update on One-Minute Rainfall Rate Measurements for Microwave Applications in Nigeria

Obiyemi

Adetan²,

Tunji³

2015

WCMC

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“…These high-frequency bands are more attractive not only for the deployment of new systems that are suitable for the advance communication technologies but also due to the congestion experienced by the available lower-frequency band. However, links propagated through higherfrequency bands (above 10 GHz), in terms of quality and availability objectives, suffer more impairment due to rain attenuation (Ojo et al, 2009;Owolawi, 2011a) among others. Raindrops absorb and scatter radio waves, leading to signal attenuation and reduction of the system availability and dependability.…”

Section: Introductionmentioning

confidence: 99%

“…However, recent research shows that these extrapolated data when used for tropical and equatorial regions will either underestimate or overestimate rain-attenuation values (Emiliani et al, 2004;Ojo and Omotosho, 2013). These performance issues are related to the limited availability of rain intensity measurements of high temporal resolution (1-min integration time) from tropical and equatorial countries, which affect the development and testing of prediction models (Ojo et al, 2009). In addition, rain-attenuation values performed better when local parameters (like point rain rate and altitude among others) are used in the prediction and not interpolated values.…”

Section: Introductionmentioning

confidence: 99%

Development of one-minute rain-rate and rain-attenuation contour maps for satellite propagation system planning in a subtropical country: South Africa

Ojo

Owolawi

2014

Advances in Space Research

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“…An overview of Lin model [7], revised Moupfouma model [8], revised Silva Mello model [9] and the newly released ITU-R model [10] is briefly presented in the following subsections.…”

mentioning

confidence: 99%

Statistical Evaluation of Measured Rain Attenuation in Tropical Climate and Comparison with Prediction Models

Yusuf

Falade

Olufeagba

et al. 2016

J. Microw. Optoelectron. Electromagn. Appl.

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Abstract-Substantial modifications have been made to the expressions for calculating distance factor and extrapolation techniques in the latest ITU-R P.530-14. However, its performance has not been rigorously evaluated in the tropical and equatorial climates. In this article, the new ITU-R method and three prediction models are validated using measurement data from tropical Malaysian climate. The data were collected on six geographically spread terrestrial microwave DIGI MINI-LINKs operating at 15 GHz. When tested against measurements, the Da Silva Mello model yields a significant improvement for the prediction of rain attenuation distributions. The prediction errors observed in the ITU-R model suggest the need for more data campaign in the afore-mentioned climates. I. INTRODUCTIONTraditionally frequencies above 10 GHz are commonly employed in the current microwave point-topoint networks, due to large bandwidth and freedom from traffic congestion. However, in these frequency bands, the performance of the fixed service (FS) is predominantly controlled by rain in 2012; however, its performance has not been largely evaluated using data collected from tropical climates. Therefore, the main aim of this article is to evaluate the performance of the newly released ITU-R model and the three afore-mentioned models, using measurement data from six locations in a tropical climate. The data used are the rain rate and rain attenuation data banks available from six geographically spread terrestrial microwave DIGI MINI-LINKs operating at 15 GHz as described in[13]. It should be mentioned here that the ITU-R P.530-14 was not yet in force when our previous works were reported. II. THEORETICAL BACKGROUND OF RAIN ATTENUATION PREDICTION MODELSRain attenuation can be conveniently defined as the product of specific attenuation (dB/km) corresponding to the point rain rate (typically measured at one end of the link) and the effective propagation path length (km) [1]. The path correction factor is defined as the ratio of effective path length to the physical path length of a microwave link, and its value is usually less than unity, except in rear cases [14].The concept of effective path length is thus a way of 'averaging out' the spatial inhomegeneity of rain rate and thus specific attenuation [15]. Note that the degree of spatial inhomogeneity in rain rate generally varies with rainfall intensity. Therefore the variation of path length reduction factor can be expressed as a function of rain rate or the corresponding time exceedance [16].Attenuation p A exceeded at p % of time can either be obtained from direct measurements, or predicted from the knowledge of long-term rainfall rate. Generally, the required inputs in most attenuation prediction models for terrestrial point-to-point microwave links are the rainfall rate exceeded at p % of time, the effective propagation path length and the link's operating frequency [7], [16]. Thus p

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One-Minute Rain-Rate Contour Maps for Microwave-Communication-System Planning in a Tropical Country: Nigeria

Cited by 33 publications

References 12 publications

Recent Update on One-Minute Rainfall Rate Measurements for Microwave Applications in Nigeria

Recent Update on One-Minute Rainfall Rate Measurements for Microwave Applications in Nigeria

Development of one-minute rain-rate and rain-attenuation contour maps for satellite propagation system planning in a subtropical country: South Africa

Statistical Evaluation of Measured Rain Attenuation in Tropical Climate and Comparison with Prediction Models

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