A PHYSICAL DISCUSSION OF THE SINGLE PARABOLIC RADIO TELESCOPE AND THE TWO-TELESCOPE INTERFEROMETER
Radio astronomy is the science of collecting extra-terrestrial radiation in the range of 15 MHz to 600 GHz to gain understanding of celestial objects. In this thesis I discuss both the single parabolic reflector radio telescope and the two-telescope radio interferometer used in radio astronomy. The total power received by a parabolic reflector is dependent on the size of the antenna, the efficiency of the reflector, the wavelength of light under observation, and the angular response of the antenna, called the "normalized power pattern". Diffraction effects limit the resolution of the single parabolic reflector. The two-telescope interferometer has increased resolution because the main beam that would be created by a single antenna is split into multiple beams through interference, with the width of one beam corresponding to the angular resolution of the interferometer. A commonly used typed of interferometer is the correlating interferometer that integrates the product of the voltages received at each telescope. The correlating interferometer does not measure the received power directly, but rather the Fourier transform of it called the visibility function. By taking many measurements with different baselines, the visibility function can be sampled over the Fourier transform (or u-v plane) space. The visibility function can then be inverted to create a radio map of the brightness distribution of the source.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:radio astronomy interferometery aperture synthesis rotational power pattern
Date of Publication:01/01/2001