Solar radiation effect on radio frequency interference (RFI) in UHF band for radio astronomy purposes
Inside of electromagnetic spectrum, astronomical objects were radiated in the range of radio frequency. The long wavelength of radio frequency travels through thc interstellar space until it reaches the earth through different mediums of propagation before being measured by a radio telescope on the...
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| Format: | Thesis Book |
| Language: | English |
| Published: |
2018.
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| Summary: | Inside of electromagnetic spectrum, astronomical objects were radiated in the range of radio frequency. The long wavelength of radio frequency travels through thc interstellar space until it reaches the earth through different mediums of propagation before being measured by a radio telescope on the ground. Ultra-high frequency (UHF) band, normally is crowded with telecommunication services where some rest frequency for astronomical lines such as H I and OH radicals lies in it. The coexistence of this band could interrupt radio astronomical observation. Another problem is that the radio signals from the telecommunication services are susceptible to interference by tropical weather factors. This interference could increase or decrease the average signal and obstruct the astronomical observation. This study is set out to obtain the relationship between solar radiation and radio signal in UHF band for radio astronomy purposes. Disconc antenna connected to low noise amplifier (LNA) and connected to spectrum analyser was used to measure the ambient radio environment in Balai Cerap KUSZA (BCK) for 24-hour observation. Then, the data measurements for six days in different months were conducted at the same site. Simultaneously, the weather station was used to measure solar radiation in W/m2 for one-minute interval. The data were analysed statistically using Spearman's correlation. The result obtained shows the radio environment within UHF band in BCK was occupied by telecommunication services (382.5 MHz, 945 MHz, 1800.0 MHz and 2160.0 MHz). However, there were still RFI free zone exist in UHF band which arc (i) between 427.5 MHz and 877.5 MHz (ii) between 990.0 MHz and 1080.0 MHz (iii) between 1215.0 MHz and 1710.0 MHz (iv) between 1912.5 MHz and 1980.0 MHz (v) between 2205.0 MHz and 2295.0 MHz and (vi) between 2385.0 MHz and 3000.0 MHz. Statistically, the effect of solar radiation is significant in all peaks. It is largely correlated with a correlation of 0.6252 (Peak 1),0.6769 (Peak 111),0.5965 (Peak IV) during January and -0.5920 (Peak II) and -0.4788 (Peak III) only during September and others shows moderate and small correlation during the other days. These findings suggest that there is no direct correlation between solar radiation and radio signal. However, the radio signals correspond well with solar radiation with supporting combination of several meteoparamctcrs. This information can be helpful to radio astronomer who searches for a site with low interference and helps communication engineers to establish a way to reduce interference caused by solar radiation on radio signal in UHF band. |
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| Physical Description: | xvi, 102 leaves: illustrations (some colour); 30 cm. |
| Bibliography: | Includes bibliographical references (p. 72-78) |