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By Claudio Maccone
- reviewed by H. Paul Schuch -
Copyright © 2009 Springer-Praxis Books (Berlin)
ISBN 978-3-549-72942-6
401 pp
Most pint and SETI League members are already familiar with the work of Dr.
Claudio Maccone, through his regular presentations at various
conferences. An advocate of gravitational lensing to dramatically
increase the sensitivity of radio telescopes, and a passionate
proponent of the adaptive Karhunen Loeve Transform (KLT) for SETI
digital signal processing, Maccone was awarded the Giordano Bruno
Memorial Award, the SETI League's highest technical honor, in 2002.
Much of the material in his latest book was previously presented as
papers at various SETICon, EuroSETI, and European Radio Astronomy Club
meetings, as well as at annual International Astronautical Congresses
around the globe. This textbook, however, is far from a collection of
conference papers. It promises to be the seminal work in a newly
emerging field of study.
The concept of gravitational lensing, long practiced by optical
astronomers, is only recently being recognized as a signal amplifying
technique for radio astronomical applications. Since the considerable
mass of a star can focus incoming photons from distant sources, the
result is a radio telescope of stellar proportions. Unfortunately, as
Maccone shows in this book, in the case of our own Sun, those photons
focus at a distance of 550 astronomical units and beyond. Thus, in
order to use the Sun as an effective gravitational lens, one must
launch radio receivers into solar orbit at greater than interplanetary
distances. The mechanics of such a space mission are discussed in the
present work, as are the communications challenges of commanding and
controlling a spacecraft in the face of three-day one-way propagation
times.
In addition to the astronautical challenges of such a mission, Maccone
discusses the need for highly optimized, computationally intensive
signal processing and analysis techniques. Not surprisingly since he
expounded on its use in his doctoral dissertation decades ago, Maccone
now advocates the KLT for this esoteric application, shows how it can
improve SETI signal-to-noise ratio by three orders of magnitude as
compared to the more conventional Fast Fourier Transform (FFT), and
introduces improved algorithms to finally make its implementation
feasible on available computational platforms. Finally, given the high
velocities of relative motion involved for space missions to 550 AU and
beyond, relativistic corrections become an important consideration,
which Maccone explores in the present work.
Two decades in the making, Deep Space Flight and Communications is the result of merging two previously published, smaller books by the author. The first, The Sun as a Gravitational Lens: Proposed Space Missions, corresponds to Part I, and the second, Telecommunications, KLT and Relativity,
corresponds to Part II of this revised and updated book. The extensive
revision process has brought Maccone's two 20th Century works firmly
into the 21st Century, and beyond.
This review first appeared on The Seti League online, 18 April 2009, and is used here by the kind permission of The Seti League and the author.
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