Introduction to the Techniques of Interferometry and Lunar Occultation in Radio Astronomy

Radio telescopes allow a 24 × 7 observation time window of those regions of the space which appear dark in the visible region. But, the major problem with a single radio telescope is its poor resolution. In this article, the method of interferometry in radio astronomy is discussed by citing the example of a two-element interferometer. Interferometry provides improved resolution.With a single telescope as well, the resolution can be improved for the radio sources along the ecliptic which are smaller in angular spread as compared to the Moon. The theoretical principle behind the technique of occultation is discussed using its optical analog of diffraction.