Evaluation of Radio Refractivity in the Troposphere Over the Big Cities of Pakistan

The study of the vertical variation of refractive power in the troposphere is necessary for the planning of radio systems. The variation of the atmospheric refractive power in the troposphere is one aspect that affects the propagation of electromagnetic waves and therefore the performance of links and communication systems. In this study, the 10-year (2008–2017) meteorological data (pressure, temperature, and humidity) from five major cities in Pakistan was used to calculate the radio refractive power. Over the entire period, the monthly average data was simulated through MATLAB to calculate radio refractivity. This work aimed to estimate the statistical variation of radio refraction due to meteorological factors, depending on the geographical area considered. The tropospheric radio refractivity results were obtained taking into account the height of the site and the height of scale parameter. The effect of temperature, pressure, and humidity on radio refraction was analyzed over 10 years (2008–2017) for five major cities of Pakistan, namely, Karachi, Quetta, Lahore, Islamabad, and Peshawar. It was revealed that the variation of radio refractive power and atmospheric pressure is higher in the rainy season than in the dry season, whereas the results indicated that the radio refractivity increased with a decrease in temperature and vice versa. The maximum relative humidity was observed as 75, 77, 89, 64, and 77 in Karachi, Lahore, Islamabad, Quetta, and Peshawar respectively, whereas the tropospheric refractivity was observed as 384, 389, 383, 437, and 378 respectively. This study found that the effect of humidity on radio refractivity is more than temperature and pressure.