Tropospheric Influence on Low-band Very High Frequency (VHF) Radio Waves (original) (raw)
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Tropospheric Influence on Ultra-High Frequency (UHF) Radio Waves
Asian Journal of Research and Reviews in Physics, 2022
This research investigates the effects of temperature and relative humidity on UHF signals. A spectrum analyzer was used in measuring UHF signals while a digital thermometer and hygrometer was used in measuring temperature and relative humidity, respectively. From results obtained, relative humidity had no significant effect on measured path loss while a positive correlation coefficient was obtained between temperature and measured path loss. This implies that an increase in temperature will lead to a decrease in received signal strength of UHF signals. Furthermore, a path loss propagation model for Calabar (P L = 37.920 + 2.796T + 0.290R +) was obtained using multiple regression analysis and we believe that the obtained result will be useful to radio engineers for UHF signal propagation in the study terrain.
Temperature Effect on the Tropospheric Radio Signal Strength for UHF Band at Terengganu, Malaysia
International Journal on Advanced Science, Engineering and Information Technology, 2016
In tropospheric layer, radio waves can propagate in a number of different physical mechanisms such as free-space propagation or line-of-sight propagation, reflection, transmission, diffraction, scattering and wave guiding. The constituents in weather such as the wind, air temperature and atmospheric water content may combine in many ways. Certain combinations can cause radio signals to be heard hundreds of miles beyond the ordinary range of radio communications. This study investigates the effect of weather (temperature) on radio wave propagation up to 9GHz. Continuous-wave (CW) envelope fading waveforms were recorded over a period of the one-hour using patch antenna. The observations were conducted at KUSZA Observatory, East Coast Environmental Research Institute (ESERI), UniSZA which is situated in Merang, Terengganu. Spectrum Analyser was used for RFI measurement and weather station for weather effect. The graphs of radio signal attenuation for weather parameter (temperature) against time were plotted. The findings indicate that there is a relationship between radio signals with the change of temperature. The correlation between RFI frequencies and temperature give negative effect for frequency 945 MHz, was r =-0.085, while for 383 MHz (r = 0.249), 1800 MHz (r = 0.268) and 2160 MHz (r = 0.134). These findings will benefit radio wave propagation research field which includes radio astronomy observations, space science, wireless communication, satellite, antenna and mobile communication and also electromagnetic radiation (EMR) research for health.
Impact of Weather Components on (UHF) Radio Signal
— This work probes the impact of major weather components on UHF radio signal. Measurements of the radio signal strength from Cross River State Broadcasting Cooperation (CRBC), (4 0 57'54.7''N, 8 0 19'43.7''E) transmitted at 35mdB and 519.25 MHz (UHF) were done in a residence along Etta-abgor, Calabar (4 0 57'31.7''N, 8 0 20'49.7''E) to ascertain the impact of the weather components: atmospheric temperature, pressure, humidity and wind on radio signals. The components: atmospheric temperature, pressure, humidity and wind speed and direction with signal strength were measured half hourly from the residence in Etta-agbor to draw a justifiable inference on the impact of the aforementioned quartet on UHF radio signal. Results indicated that radio signal strength is inversely proportional to atmospheric temperature, pressure and humidity; provided that for any of the giving components, others were observed constant, including the wind speed and direction, since it has been erected that wind has a marked effect on radio signal. The correlation of the signal strength and atmospheric temperature, pressure and humidity were respectively r =-0.94,-0.99 and-0.93 and the equation S =
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Atmospheric impairment-induced attenuation is the prominent source of signal degradation in radio wave communication channels. The computation-based modeling of radio wave attenuation over the atmosphere is the stepwise application of relevant radio propagation models, data, and procedures to effectively and prognostically estimate the losses of the propagated radio signals that have been induced by atmospheric constituents. This contribution aims to perform a detailed prognostic evaluation of radio wave propagation attenuation due to rain, free space, gases, and cloud over the atmosphere at the ultra-high frequency band. This aim has been achieved by employing relevant empirical atmospheric data and suitable propagation models for robust prognostic modeling using experimental measurements. Additionally, the extrapolative attenuation estimation results and the performance analysis were accomplished by engaging different stepwise propagation models and computation parameters often ut...
Signal strengths measurements were obtained half hourly for some hours and simultaneously, the atmospheric components: atmospheric temperature, atmospheric pressure, relative humidity and wind direction and speed were registered to erect the effects of air density and dew point temperature on radio signals (electromagnetic waves) as they travel through the atmosphere and air radio wave refractivity. The signal strength from Cross River State Broadcasting Cooperation Television (CRBC-TV), (4057'54.7''N, 8019'43.7''E) transmitted at 35mdB and 519.25 MHz (UHF) were measured using a Cable TV analyzer in a residence along Ettaabgor, Calabar, Nigeria (4057'31.7''N, 8020'49.7''E) using the digital Community – Access (Cable) Television (CATV) analyzer with 24 channels, spectrum 46 – 870 MHz, connected to a domestic receiver antenna of height 4.23 m. Results show that: on the condition that the wind speed and direction are the same or (0 mph NA), the radio signal strength is near negligibly directly proportional to the air density, mathematically Ss / ∂a1.3029 = K, where Ss is Signal Strength in dB, ∂a is Density of air Kg/m3 and K is constant; radio signal strength is slightly inversely proportional to the dew point temperature; irrespective of the wind speed direction, mathematically, Ss x Td0.761 = K at same wind speed and direction, where Ss is Signal Strength in dB, Td is Dew point temperature in 0C and K is the constant; also, the air radio wave refractivity is slightly directly proportional to the air density, not taking into cognizance the wind speed and direction, since the radio refractivity formula is not a function of wind, mathematically, NR / ∂a0.4443 = K where NR is Air radio wave refractivity in inHg20F1/2%1/3, ∂a is Density of air Kg/m3 and K is constant; finally, the atmospheric radio wave refractivity is slightly directly proportional to the dew point; irrespective of the wind speed direction, mathematically Ss / Td0.2662 where Ss is Signal Strength in dB, Td is Dew point temperature in 0C and K is the constant.
Effect of Humidity on Tropospheric Received Signal Strength (RSS) in Ultra-High Frequency (UHF) Band
Journal of Physics: Conference Series, 2020
The variation of weather conditions can affect the performance and quality of a communication system and sensor network. Therefore, it is vital to explore the factors that influence the quality of the radio signal to adapt to weather conditions. This paper describes the tropospheric effect of the meteorological parameter (humidity) for Ultra High Frequency (UHF) band at KUSZA Observatory (KO), UniSZA, Terengganu. Received signal strength (RSS) and humidity were collected using spectrum analyser and weather station respectively for 24 hours in a rainy and a sunny day. Statistical analysis was used to determine the relationship between humidity and RSS. The results show that variation in humidity conditions give RSS with negative correlations in both conditions. The correlation of the RSS and humidity at both observation days (r r =correlation of frequencies on rainy day, r s = correlation of frequencies on sunny day) for frequency 382.
Impact of Atmospheric Temperature on (UHF) Radio Signal
— Radio signal strengths from Cross River State Broadcasting Cooperation Television (CRBC-TV), (4 0 57'54.7''N, 8 0 19'43.7''E) transmitted at 35mdB and 519.25 MHz (UHF) were measured using a Cable TV analyzer in a residence along Etta-abgor, Calabar (4 0 57'31.7''N, 8 0 20'49.7''E) simultaneously with the meteorological components (weather parameters): atmospheric temperature, atmospheric pressure, relative humidity and wind speed and direction to ascertain the impact of atmospheric temperature on radio signals. The meteorological components with signal strength were measured half hourly from the residence for over 24 hrs to draw a justifiable inference on the impact of the atmospheric temperature on the radio signal. Results indicated that radio signal strength is inversely proportional to atmospheric temperature; provided that, other measured metrological components were observed constant, including the wind speed and direction. The correlation of the signal strength and atmospheric temperature was r =-0.93 and the equation S =K/T at constant atmospheric pressure, relative humidity and wind speed and direction was postulated, where S, T and K are Signal strength, Atmospheric temperature and Constant respectively.
Impacts of Weather and Environmental Conditions on Mobile Communication Signals
Journal of Advances in Science and Engineering, 2018
The impacts of weather and environmental conditions on mobile communication signals were determined in this study. A Glo mobile communication network operating in the 900MHz band was considered. The Glo fixed base transceiver station (BTS) location at Gloworld in Benin City was considered. A frequency-signal tracker software, version 2.5.1 was installed and configured into a notebook Intel palm top, relative parameters data were obtained from 200 meters from the Glo BTS from 28 th of July to 31 st of August 2016, with data obtained hourly. Morning, afternoon and evening, and dry weather, fog weather and raining conditions was based on the statistical central tendency parameters. The average refractivity gradient observed was-61.3 N/km. It was observed that dry weather, signal strength variation was within 32 dBm, fog, variation was within 34 dBm range, while the variation of rain was within 38 dBm range indicating higher variation. It was observed that the more the mobile station move away from the BTS the higher the signal loss and that temperature and refractivity gradient has 0.50 and 0.42 positive correlations. In addition, relative humidity and pressure possesses negative correlations of-0.50 and-0.44 respectively.
Radio Propagation Measurements In Brazil: Clear Air and Rainfall Effects
Journal of Communication and Information Systems, 1994
Methods for the prediction of propagation effect in radio communications systems are usually semi empirical and dependent on the statistical behaviour of radiometeorological parameters, such as refractivity gradient and rainfall rate. The data basis currently available for the development, testing and application of these methods have been obtained, mostly, on experiments performed at sites in temperate climates. In the last 15 years several propagation measurements' campaigns have been carried out in Brazil, aiming to provide data for the development and application of prediction methods in tropical and equatorial climates. In this paper, results from these experiments are reviewed and new data made available in experiments now underway are presented.