Book review

---

Fourier Transform Spectrometry By Sumner P. Davis, Mark G. Abrams and Janes W. Brault. Pp 160. Academic Press. 2001. Price £53.95. ISBN 0-12-042510-6. Search PubMedIt would be interesting to have information on how the considerable number of Fourier transform spectrometers in laboratories world-wide are distributed among various types of users; organic chemists, analytical spectroscopists, those studying fundamental molecular structural constants, astrophysicists and others. Such information would be very apposite in assessing the potential readership for what is, undoubtedly, a very thorough specialist account of the technique.

This is not the book for neophytes; their needs are well catered for by several more general texts on methods and applications of infrared spectroscopy. Nor will it satisfy those who wish to know more about instrument fabrication, a topic which the authors confess to have conspicuously avoided. However, what this book sets out to do, namely to provide expert advice based on enormous practical experience of the use of Fourier transform spectrometry for high resolution studies in astrophysics, atomic and gaseous molecular spectroscopy, it does exceedingly well.

Following a brief introductory chapter which, like those that follow, ends with a very useful summary of matters discussed, the authors then demonstrate why Fourier transform spectrometry is such a valuable technique. This sets the scene for a series of chapters in which various aspects of the technique are discussed in depth. The theory of the ideal instrument is followed by as much of the formal mathematics of Fourier analysis as is required by physicists/spectroscopists. In this chapter, and the book as a whole, diagrams are used to great effect to facilitate understanding of the more difficult mathematical concepts.

The authors then move on to non-ideal (real-world) interferograms, obtained from laboratory instruments which operate with finite path differences and optics of finite size. This chapter is followed by one on working with digital interferograms and the various problems arising from the discrete sampling of the interferogram. Some of the points discussed are relevant in the wider context of discrete sampling of other types of digital data. The authors then move on to phase corrections, which are very much tied to Fourier transform spectrometry.

The effects of noise in its various forms are discussed in depth, to considerable advantage. The summary at the end of this chapter is particularly valuable for those disinclined to work through a fairly high density of equations. Line positions, line profiles and line fitting are considered next, primarily in the context of sharp emission and absorption lines. Some of the methods described, most notably least squares fitting of line profiles to specific mathematical functions, will be of value to anyone faced with the separation of much broader overlapping peaks, a situation in which the simple Lorentzian profile is wholly satisfactory.

The formal text concludes with a chapter on the processing of spectral data and another written as an addendum to update earlier parts of the text. In the latter the section on apodization should be of wide interest but the account of echelle gratings, although fascinating, is for specialists only. The book concludes with four bibliographies, covering chapter by chapter information, the history of the technique, authors and applications. This final bibliography will be very useful for those with interests akin to the work of the authors, but much less so to others.

All users of Fourier transform spectrometers with rather more flexibility and capability than basic instruments designed for routine infrared spectroscopy will benefit from reading this book. They will then obtain better value for money from their spectrometers.

W. F. Maddams
Barnstead, Surrey, UK

---