Customer Reviews

An Introduction to Radio Astronomy

5 star:		(2)
4 star:		(2)
3 star:		(2)
2 star:		(0)
1 star:		(1)

 

 

This is a most excellent introduction to Radio astronomy. The book is well layed out, has good explanations and provides many leads to further study. The book's contents are:

Radio telescopes as antennas. Signal detection and noise. Single-aperture raido telescopes. The two element interferometer. Aperture synthesis. The absorption, amplification, refraction and attenuation of radio waves. Galactic continuum radiation. The interstellar medium. Galactic Dynamics. Stars. Pulsars. Radio galaxies and quasars. Cosmology and the cosmic microwave background. Cosmology: discrete radio sources and gravitational lenses. The place of radio in astronomy.

An Introduction to Radio Astronomy (1997) targets astronomy graduate students and others committed professionally to radio astronomy. The authors - two noted radio astronomers, Bernard F. Burke and Francis Graham-Smith - also hope to interest optical astronomers and others who want to be informed of the principal ideas current in radio astronomy, and may even be thinking of carrying out radio observations that would complement other work in progress.

With a background in geophysics, I did not always find An Introduction to Radio Astronomy to be easy going, but most topics were not out of reach. That is, readers with some background in physics, electrical engineering, and/or signal processing will find substantial familiar ground, including electromagnetics, thermodynamics, Fourier analysis, and spectral analysis. I give five stars to this not-so-easy, self-contained, advanced introduction to radio astronomy.

I found the first six chapters (about 80 pages) to be the most challenging, perhaps due to my limited familiarity with radio telescopes. Key topics included radio telescopes as antenna, signal detection and noise, single-aperture radio telescopes, the two-element interferometer, and aperture synthesis.

Chapter 7 - the absorption, amplification, refraction, and attenuation of radio waves - addresses radiative transfer, astrophysical masers, radio propagation through ionized gas, Faraday rotation of polarized waves, scintillation (radio amplitude variations akin to the optical twinkling of stars), and radio propagation in the earth's atmosphere. Take your time with this chapter as the authors frequently return to these topics.

The remaining nine chapters offer a wide-ranging review of the radio universe and are more immediately accessible to a wider audience. The chapter titles are Galactic Continuum Radiation, The Interstellar Medium (ISM), Galactic Dynamics, Stars, Pulsars, Radio Galaxies and Quasars, Cosmology and the Cosmic Microwave Background (CMB), Cosmology: Discrete Radio Sources and Gravitational Lenses, and The Place of Radio in Astronomy.

Two Suggestions: I strongly urge the reader to stay the course with the first seven chapters as the later chapters require a basic understanding of radio observation methodologies, antenna temperature, radio brightness temperature, non-thermal radiation, 21 centimeter radiation, bremsstrahlung emission spectra, etc.

Also, a reader that is relatively new to radio astronomy will find it helpful to read at an early stage the three appendices: Appendix 1 - a concise review of Fourier transforms, intended as a review, not as a self-tutorial, Appendix 2 - a general overview of celestial coordinates , distance, and time, and Appendix 3 - a fascinating account of the origins of radio astronomy (1932 -1954).

In a graduate course that I was taking on Radio Astronomy, this book was often criticized by the students. In short, it was a difficult book to wade through. If my education had included more study of the Greek alphabet, maybe the long recitations of formulae would not have made this the book you can't pick up. I'm just going to assume that all the math you would want is right here but you don't get to see them in action. It is pretty clearly a course textbook but there are no problems to solve and no attempt to work through examples.

I do want to make a strong plug for the 3 appendices. One is a good introduction to Fourier transforms (27 formulae in 8 pages without any examples worked out - typical for this book); the second discusses celestial coordinates, distances and time; the third is the best 7 page history of radio astronomy that you will find.

I don't understand those who gave this terrible book a 5 star review. The information no doubt is in there, but the language and presentation of the information are very poor. It's almost as if the authors had set out to provide the most arcane presentation possible, so that only the elect could understand it. In my view this is not an introductory book; neither is it a good text book. I confess to finishing my unit in radio astronomy by using this book as little as possible - and I'm not alone in that.

Well, I got to say, this does pass the test of a pretty good introduction to the subject for someone with a good technical background. What others have said stands. That said, the careful reader with be constantly annoyed with the flagrant basic errors of math and language that frequent this text. Where the heck were the editors and proof-readers for this thing? Very often equations are written that are just flat out wrong due to omissions or typos that the reader must deduce. In other cases statements are made in the text I suppose to try to explain a point but in the end just demonstrate that the author's had absolutely no idea what they were talking about since what they state is in fact just plain wrong, oftentimes just plain bad basic math. Finally there is a general sloppiness to the writing style with the frequent use of ambiguous pronouns that often point to the wrong subject or predicate.

Some small examples:

Eq 5.8 is s = s0 + d

(Vectors, little hats over s and s0 to indicate unit vectors, and d is actually the greek letter sigma).

The text following states:

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where d is a small vector, normal to s0. (It must be normal, since both s and s0 are unit vectors).
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The parenthetical adds absolutely nothing to the understanding of the problem and is IN FACT WRONG. If s and s0 are unit vectors then d CANNOT be normal to EITHER ONE OF THEM. Basic vector math folks, in fact just a basic understanding of a right triangle. Amazing that the authors went out of their way to make a statement that not only contains no illuminating information but is flat out wrong. Not only that, but no proof-reader or editor noticed this obvious error - this is high-school math here. Other examples such as this are throughout the text.

Another example highlighting the awful writing style:

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The autocorrelation function is related to the spectrum of f(t); for zero time shift it is simply its square.
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Try reading that a few times. The first clause is true. The second clause is extremely confusing. I love that "it" and "its" are in the same clause for starters. To top it off "its" refers to f(t) which would be your last guess unless you already knew what they were trying to say. It is plain bad english. Again, numerous examples throughout the text.

I can't really fault the authors to much here. Writing a book is a very hard task and the authors have taken on a very wide subject and as far as information content goes have done a very good job. Unfortunately it reads a bit like some sloppy class notes. Often the most knowledgable folks, and even the best teachers, are not the best writers. It is the job of the editor to bridge the gap here. In this case the editors at Cambridge University Press should be ashamed of themselves. They have let both the authors and their readers down.

Anyway, I guess I'd recommend, but get ready to be confused and annoyed. And not by the subject matter which is actually quite accessible.

A comprehensive and modern text book on the subject , I found it well presented and feel it should appeal to both astronomy students as well as radio astronomy amateurs .

This book is a great Radio Astronomy text for the undergraduate major or the graduate level. It is a little advanced for most of my students....