Techniques of Radio Astronomy

TL;DR

This paper reviews the historical development, technical techniques, and scientific contributions of radio astronomy, highlighting advances in instrumentation, imaging, and global observatories over nearly a century.

Contribution

It provides a comprehensive overview of radio astronomy techniques, including calibration, receiver systems, and aperture synthesis, emphasizing recent technological and scientific progress.

Findings

Aperture synthesis produces high-resolution images.

Radio astronomy has significantly advanced our understanding of the universe.

Global radio observatories are on the horizon.

Abstract

This chapter provides an overview of the techniques of radio astronomy. This study began in 1931 with Jansky's discovery of emission from the cosmos, but the period of rapid progress began fifteen years later. From then to the present, the wavelength range expanded from a few meters to the sub-millimeters, the angular resolution increased from degrees to finer than milli arc seconds and the receiver sensitivities have improved by large factors. Today, the technique of aperture synthesis produces images comparable to or exceeding those obtained with the best optical facilities. In addition to technical advances, the scientific discoveries made in the radio range have contributed much to opening new visions of our universe. There are numerous national radio facilities spread over the world. In the near future, a new era of truly global radio observatories will begin. This chapter contains a short history of the development of the field, details of calibration procedures, coherent/heterodyne and incoherent/bolometer receiver systems, observing methods for single apertures and interferometers, and an overview of aperture synthesis.