Single Dish Radio Astronomy: Introduction

Introduction

Over 60 years ago an amateur astronomer built the first single-dish radio telescope in his back yard. From these humble beginnings, the new science of radio astronomy was born. For nearly a decade Grote Reber, engineer by day and observer by night, was the sole pioneer in this promising new field. It was not until the mid-1940’s that the astronomical community realized the importance of radio astronomy and began constructing instruments for their own research.

Reber's backyard radio telescope.

Jocelyn Bell Burnell, discoverer of the pulsar, standing in front of the Cambridge radio telescope on which the observations were made.	Over the last half-century astronomers have employed a wide variety of designs for their telescopes. From the Cambridge dipole array consisting of a field-full of fence posts with wire strung between them, to the 300-meter Arecibo spherical reflector built into a natural limestone hollow in the ground, each of these unique instruments have seen their successes. However, the steerable parabolic reflector, first employed by Reber, remains by far the most popular design.
		Arecibo Observatory, Puerto Rico At 1000-feet in diameter and 400-feet deep, it is the largest single-dish radio telescope in the world. Image courtesy NAIC, Arecibo Observatory

Despite the introduction of the interferometer, a collection of antennas working in concert to yield increased sensitivity and resolution, the single-dish radio telescope has been able to retain its astronomical niche by excelling at certain kinds of observations.

The Very Large Array in New Mexico, a 27 element interferometer. Image Š2000 C. Gino

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