Performance evaluation of some rain rate conversion models for microwave propagation studies

Igwe, K. C.; Oyedum, O.D.; Ajewole, M. O.; Aibinu, Abiodun Musa; Ezenwora, J.A.

doi:10.1016/j.asr.2021.01.055

Cited by 5 publications

(3 citation statements)

References 16 publications

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“…In this paper, the vertical profile of radio refractivity and refractivity gradients is evaluated in Abuja, the Federal Capital Territory of Nigeria, a tropical country. Similar studies have been carried out in other locations in Nigeria [10][11][12][13][14][15][16][17] but there is need for continuous data update in the light of climate change.…”

Section: Introductionmentioning

confidence: 71%

Evaluation of the Vertical Profile of Radio Refractivity and its Gradients in a Tropical Atmosphere

Igwe,

Tukur

2023

JAITA

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This paper evaluates radio refractivity and its gradients over Abuja, the Federal Capital Territory of Nigeria, using five years upper air meteorological data obtained from the Nigerian Meteorological Agency (NiMet). From the results obtained, radio refractivity was observed to decrease with increasing altitude. Also, higher refractivity values were observed in wet season, while lower values were recorded in dry season. An average refractivity value of 326 N-Units was obtained at 1 km altitude, while average refractivity gradient values of -34 N-Units/km and -40 N-Units/km were recorded for the dry and wet season months respectively. A total average value of -38 N-Units/km for refractivity gradient was obtained for the five-year study period, thus making the atmospheric condition over Abuja to be sub-refractive. The effective earth radius factor (k-factor) computed for the location was also observed to be higher in the wet season months than the dry season months. An average k-factor value of 1.32 was obtained for the study period.

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Section: Introductionmentioning

confidence: 71%

Evaluation of the Vertical Profile of Radio Refractivity and its Gradients in a Tropical Atmosphere

Igwe,

Tukur

2023

JAITA

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“…International Telecommunication Union (ITU) introduced a global rain attenuation model to characterize the effect of rain on the propagating signal at wide band of frequencies. The applicability of ITU-R models for rainfall rate and rain attenuation is a subject of recent research at different levels of frequency and different locations over the globe 40,41,42 . However, the validity of this model in tropical regions is still an open question for research.…”

Section: Introductionmentioning

confidence: 99%

Comparison of ITU-837 Models Performance in Predicting Malaysia's Rainfall Rate and Rain Attenuation CCDF

Al-Samawi

Nissirat

Shayea

et al. 2022

Preprint

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This paper investigates the performance of different ITU models in predicting Malaysia s tropical rainfall rates and rain attenuation. This investigation is considered at 26GHz mm-wave frequency, and three datasets collected at different regions in Malaysia with emphasize on the latest dataset in Skudai in 2012. The data collected has rainfall rate and rain attenuation measurements for a continuous year at 1 spm sampling rate. Nonlinear regression is used to estimate best fit parameters for comparison with ITU-R p.837-1 with rain zone data, ITU-R p.837-6 as method 1 and ITU-R p.837-7 as method 2. Results show that ITU method 2 outperforms all the models with RMSE in the range of 12.72 mm/hr and 3.51 dB/km for rainfall rate and rain attenuation respectively. Conversely, absolute error at 0.01% of time showed superiority of ITU-R p.837-1 tropical recommendation with absolute error in the range of 0.39 mm/hr and 4.16 dB/km for rainfall rate and rain attenuation respectively. All models showed significant deviation from the measurements and the best fit at lower than 0.01% of time, with minimum deviation observed for of ITU method 2 in that range. Worst month parameters estimation using ITU method2 is in good match to the best fit estimation.

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“…

Rain rate is usually considered a very important parameter when analysing rain-induced attenuation [1,2]. For effective and accurate analysis of rain-induced attenuation, conversion of rain rate from any integration time to 1minute has been an important and accepted approach, especially when one-minute local data is not available [3,4]. Recent efforts have been made in North Central Nigeria in this regard [5,6].Based on the different physical principles of measurement systems, whether it is direct or indirect or whether it is ground-based or space-based, a number of rainfall-measuring methods exist.

…”

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confidence: 99%

Derivation of Regression Coefficients and Conversion Factors for 1-Minute Rain Rate Statistics in A Tropical Environment

Igwe¹

2023

JAITA

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An important characteristic of rainfall levels at a particular place is the statistical distribution of rainfall rate. In this paper, 1-minute, 5-minute and 30-minute integration time rainfall data were obtained from three different weather stations in Physics Department, Federal University of Technology, Minna, North Central Nigeria. The aim is to derive regression coefficients and conversion factors for predicting rainfall rate of 1-minute integration time from rainfall rates of other integration times. This was achieved by employing Segal, Flavin and Watson rain rate models. The results obtained revealed that there is a power law relationship between 1-minuterain rate (R1) and the equiprobable 5-minute rain rate (R5); and between 1-minute rain rate (R1) and the equiprobable 30-minute rain rate (R30). Also,it was observed that the values of regression coefficients a and b, and conversion factors Ce and CR derived in Minna were different from values derived at other locations in and outside Nigeria when comparisons were made. These discrepancies are attributed to the differences in climatic conditions between the regions among other factors. Therefore, these findings have further corroborated claims by earlier researchers that different regression coefficients and conversion factors are needed for different locations for 1-minute rain rate conversion.

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Performance evaluation of some rain rate conversion models for microwave propagation studies

Cited by 5 publications

References 16 publications

Evaluation of the Vertical Profile of Radio Refractivity and its Gradients in a Tropical Atmosphere

Evaluation of the Vertical Profile of Radio Refractivity and its Gradients in a Tropical Atmosphere

Comparison of ITU-837 Models Performance in Predicting Malaysia's Rainfall Rate and Rain Attenuation CCDF

Derivation of Regression Coefficients and Conversion Factors for 1-Minute Rain Rate Statistics in A Tropical Environment

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