CONSTRUCTION AND OPERATION OF A RADIO TELESCOPE TO DETERMINE THE SURFACE TEMPERATURE OF THE SUN

ABSTRACT

Radio astronomy is the study of celestial objects that give off radio waves. The main difficulty faced by amateur astronomers in building radio telescope is the signal radiated from cosmic sources. Most of these signals are usually very weak and their magnitude may be comparable with thermal noise. The purpose of this thesis is to provide effective approach to design, develop an affordable simple radio telescope capable of collecting and analyzing RF energy or electromagnetic radiations that are emitted by bodies in space, very much as optical astronomers use light energy collected by telescopes. The main aim is to determine the surface temperature of the Sun with this affordable simple radio telescope that is built. The total temperature of the radio telescope system and beamwidth of the DSTV dish antenna from the Sun was also calculated. In this study, the basic radio telescope is based on the ―Itty-Bitty‖ design, the major components include a modified TV dish antenna, Satellite Finder, Low Noise Block (LNB), Arduino and a PC. The dish collects the radio signals from space and focuses them on the LNB and the satellite finder deflects, notifying the presence of signal and strength of the signal collected by the dish with an e mitting sound. The low-noise block (LNB) is the receiving device mounted onto the satellite dish. It is a preamplifier/down converter that converts the satellite signals from around 12 GHz down to around 2.4 GHz. The arduino connected to the satellite finder is acting as an interface that converts the signal strength into an amplitude modulated tone. The tone is fed into the PC sound card, then the PC and radio skypipe software graphically displays the signal strength as a function of time. Finally, Fast Fourier Transform (FFT) in MATLAB software installed in the PC is used to interpret the graph.The telescope uses dish antenna and a receiver operating at Ku band (10-12 GHz). By observations and analysis of the electromagnetic radiations collected from the Sun for three to four days, the temperature of the Sun was calculated to be xi K. Although this measured value is very negligible compared to the standard surface temperature of the Sun which is approximately 5,778K, it is so due to energy losses of the radio waves or electromagnetic radiations which in turn leads to reduction in their strength before reaching the dish antenna of the radio telescope here on earth.