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.Keywords-temperature effect, radio signal propagation, radio astronomy, radio frequency interference.

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Radio signals detected from the ground are very weak since it travels far from the universe. Radio wave carries photons with low energies compared to other electromagnetic spectra such as visible light, ultraviolet, X-rays, and the most energetic electromagnetic wave is gamma-rays. The microwave region is the shortest wavelength of radio waves. Hence, microwave photons have greater energy. Radio astronomy studies are restricted due to radio frequency interference (RFI) that produces by human daily activities. If this disturbance is not shrinkage, it poses critical problems in radio observation. There are many factors of man-made RFI, such as, the availability of mobile telecommunications, radio transmission, TV broadcasting, satellite communication, vehicular traffic area, power transmission line and many more. In this paper, we present a preliminary study of the radio sources (electronic system in the car) from the vehicular traffic area (highway) on radio astronomy observation. This study is important to assess how the vehicles  affect the radio signal in radio astronomical sources of low frequency such as hydrogen line and deuterium (which wavelength more than 1mm). These research findings would benefit radio astronomy research, especially to profile the RFI pattern in Malaysia.

Sun is constantly produced mass and radiation during its natural activities, which will interact with ionosphere and affect the earth weather. In radio astronomer community, CALLISTO is used to capture the radio signal comes from solar activities such as solar burst. Solar flares and Coronal Mass Ejections (CMEs) were closely associated with the production of solar radio burst Type II and III. However, the determination of solar burst existence is done manually using spectrograph which appears for every 15 minutes. In order to assist the solar radio researcher to speed up the process of solar burst identification and detection, this work presents a new algorithm to auto classify solar radio burst Type II and III. The value of frequency drift was used as the main idea in this auto classify algorithm because it can easily implemented using MATLAB. There are three main steps involved named as pre-processing, identification and classification. Auto calculation of frequency drift burst on spectra was obtained from two parts which are frequency axis (df) and time axis (dt). The results of the frequency drift implementation in classification algorithm show that the algorithm developed gave almost similar determination as in manual detection. However, there are always have rooms for improvement for better detection system in future which may include specific characterization of bursts and improved noise elimination.

An appropriate site selection for radio astronomy observation is very important in order to find a low level site in RFI value. The aim of this study is to select the best possible factors for astronomical observation sites. There are many factors such as slope, raindrop, river, population density, road network, land used, wireless telephone technology interrupts radio astronomy observation. In this study, we have reported one of the factors that affect radio observation which is rain effect. The site selection study is the most crucial part of decision makers proposes where to build an astronomical observatory, especially in radio astronomy with a maximum efficiency. The observation apparatus was set up to study the effect of rainfall and raindrop to the radio signal. We found that, in the inside observation, we found that spectral lines (Deuterium, Hydrogen, and two Hydroxyl lines) show that the rain gives no effect to radio signal in those windows. We also found that there is very small fluctuate value are very small (about -2 dB) for outside observation. It can be considered has no significant effect on rain below 2.9 GHz.