Validation of ITU-R Model for Atmospheric Refractivity Profile in A Tropical Region

Yıl 2010, Cilt: 2 Sayı: 4, 72 - 82, 01.12.2010

O. Agunlejika T. İ. Raji

Öz

This paper presents the results of an investigation of the applicability of the International Telecommunication Union Recommendation P453 model for the refractivity profile of a typical troposphere of the tropics. Measurements of refractivity at the first 200 m altitude taken over one year in Akure, southwest Nigeria have been used. The results showed that the model using the scale height of 7.35 km and 7 km as recommended for global and tropical environments respectively gave reasonably accurate results for the refractivity at the altitude of 50m and 200m for seven out of the twelve months of the year. The scale height of 7 km gave a better result at 50 m altitude while 7.35 km scale height gave a better performance at 200 m. The refractivity values given by the models deviate from the measured values at other altitudes. The results also show discrepancy between model values and measured at all level in the months of October, November, December and January. These results suggest that there might be a need for a re-evaluation of the refractivity model for the tropical region

Anahtar Kelimeler

Refractivity profile, ITU-R model, Tropical region, Troposphere, radiowave propagation

Kaynakça

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• [8] ITU-R, “Radio Refractive Index: its formula and refractivity data” Rec. P 453-9, International Telecommunication Union, Geneva, 2003.
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