Customer Reviews

Astronomical Algorithms

5 star:		(13)
4 star:		(5)
3 star:		(1)
2 star:		(1)
1 star:		(0)

 

 

This is a very good and very complete reference, although it lacks the fundamentals behind the algorithms (which indeed is not the intention of this book). Many algorithms are however just curve-fitting: very accurate in the proximity of the year 2000 but they will produce nonsense if you calculate "very far away" from 2000, so it is not of eternal value... One has to take care of the various units and reference frames being used (but that's an essential part of astronomy). I'm glad I bought it.

Once again author Jean Meeus demonstrates his expertise in astronomical positioning and applied mathematics with Astronomical Algorithms. He brings us into the 21st century with the new J2000.0 epoch and FK5 system. His chapters on the primary corrections of precession, nutation, parallax, and aberration are thorough and presented in both the equatorial and ecliptic coordinate systems. Planetary positioning, including the Sun, is provided by the principal elements of Bretagnon and Francou's VSP087 theory. Chapront's ELP-2000/82 theory provides Lunar positioning. The Galilean satellites of Jupiter are located with Lieske's E2x3 theory. The author systematically steps us through each method with real examples.

There are practical chapters on Julian Dates, Sidereal Time, Dynamical Time, Rising and Setting, Coordinate Transformations, Equinoxes and Solstices, and Refraction. Mathematically useful chapters include Interpolation, Curve Fitting, Iteration and Sorting. For comet and minor planet watchers, there are chapters on Elliptic, Parabolic and Near Parabolic Motion. Times of conjunctions, elongations, and oppositions can be calculated accurately using the chapter on Planetary Phenomena. There are chapters for the physical ephemerides of Mars, Jupiter, Saturn and the Moon, including how to find position angle, illuminated fraction, and visual magnitude. In addition, there are Phase, Apogee and Perigee, Node and Libration chapters for the Moon. Solar observers can use the chapter on heliographic coordinates, based on Carrington's rotation number, to plot and track sunspots. For eclipses, Meeus gives us a chapter that, with relatively modest calculations, predicts the time, magnitude and duration for lunar and solar eclipses with remarkable accuracy. There is even a chapter on how to construct a planar sundial. Even Pluto, which is calculated in astrometric place, has a chapter.

You will not see the usual vector / matrix notation, the actual equations are provided for us instead. Throughout the book, definitions are given for the astronomical terms, each of which is summarized in the glossary. Beginning with the chapter on Accuracy, he consistently reminds us what constitutes significant digits and why rigorous expressions are often not necessary. For example, there are alternative, low precision algorithms which are quite accurate and provide a good starting point for learning the concepts.

This reviewer has coded most of the algorithms in the book and generated very accurate geocentric and topocentric apparent place ephemerides for the Sun, Moon, planets and the Galilean satellites.

A knowledge of plane and spherical trigonometry along with basic algebra and calculus is recommended, but the programming inclined should find rewarding challenges in translating these algorithms into computer programs and begin creating their own ephemerides.

This excellent book is the renewed and extended version of Astronomical Formulae for Calculators by Jean Meeus. If you intend to buy a book about Astronomical Algorithms, don't buy them both, choose between the cheaper and less extended Astr.Form. or the more expensive but more valuable Astr.Algor. The 'Morsels' are an addition to the 'Algorithms', and I suggest you buy it only if you already know the Algorithms and want to go further.

Okay, so you're a programmer and an astronomer? Then this book is for you! No other book has a complete programs and algorithm for computing problems in astronomy. You wan't to convert astronomical coordinate system? Calculate the date of easter? Counting Julian Day Number? Determine the date of perihelion and aphelion of all the nine planets? Computing the positions of the satellite of Jupiter? Everything can be done, and much-much more! What surprises me is that not only that this book covers more advanced topics like calculating eclipses and moon phases, but also a few popular and useful topics like calculating easter, which is usually don't covered by books of similar topic.

Several method and tips for programming are also covered here, along with some method for accuracy. However, that's about all. You don't know how to program? Then learn some Pascal or Fortran from other books. You don't know a bit about astronomy? Well, this book cover some basic theory, but that's just about all. So one of the drawback of this book is that it doesn't cover much ground on the teory. The reader is expected to have some background on it. Reasonable, since this book is meant to become a textbook for astronomical computations.

With his special knack for computations of all sorts, Jean Meeus has made the essentials of powerful new machine methods for modeling the motions and interactions of bodies within the solar system available to us all. The second edition contains new chapters about the Jewish and Moslem Calendars, the satellites of Saturn, and a new Appendix giving expressions (polynomials) for the heliocentric coordinates of the giant planets Jupiter to Neptune from 1998 to 2025.

Meeus describes in detail a great number of astronomical calculation methods. The books starts with a general discussion on precision of calculations. It goes on to discuss time related issues before getting into celestial bodies algorithms.

All calculations are fully explained and illustrated by many examples. A handy format, if you want to implement the methods in any computer language. Source code (C and Pascal) is also available (separately) from the publisher, Willmann-Bell.

I found this book to be the most complete source for astronomical calculations. Methods to find position of planets, for example, are very well explained. These I could not find in any other source.

I used the book a lot in my celestial navigation software Navigator Light.

This book was written with the programmer in mind. My only criticism is that there is not enough comments explaining how Mr. Meeus came up with his algorithms. He presents portions of it as 'black magic'. The algorithms work, but why?

As an engineering student who wanted to write an astronomically-based piece of software for his senior project, I found Meeus' book indispensable. His descriptions of various formulae needed some time to wade through; in spite of the learning curve, however, the algorithms were quite useful. This is definitely recommended *only* for the serious analyst who is willing to supplement the text with other authoritative sources. Still, in what this book attempts to accomplish, I have not found its equal.

I am an amateur astromer and amateur software designer. Meeus' book is absolutely invaluable for producing programs that require knowledge of the locations of the Sun, Moon and planets at any particular time. It's worth the price alone for the algorithms of Jupiter's natural satellites. The simple algorithm for lunar eclipses is amazing. I have written countless sub-routines and functions based on both large and small bits of data in Meeus' book. Thank you, Jean Meeus!

Once again author Jean Meeus demonstrates his expertise in astronomical positioning and applied mathematics with Astronomical Algorithms. He brings us into the 21st century with the new J2000.0 epoch and FK5 system. His chapters on the primary corrections of precession, nutation, parallax, and aberration are thorough and presented in both the equatorial and ecliptic coordinate systems. Planetary positioning, including the Sun, is provided by the principal elements of Bretagnon and Francou's VSP087 theory. Chapront's ELP-2000/82 theory provides Lunar positioning. The Galilean satellites of Jupiter are located with Lieske's E2x3 theory. The author systematically steps us through each method with real examples.

There are practical chapters on Julian Dates, Sidereal Time, Dynamical Time, Rising and Setting, Coordinate Transformations, Equinoxes and Solstices, and Refraction. Mathematically useful chapters include Interpolation, Curve Fitting, Iteration and Sorting. For comet and minor planet watchers, there are chapters on Elliptic, Parabolic and Near Parabolic Motion. Times of conjunctions, elongations, and oppositions can be calculated accurately using the chapter on Planetary Phenomena. There are chapters for the physical ephemerides of Mars, Jupiter, Saturn and the Moon, including how to find position angle, illuminated fraction, and visual magnitude. In addition, there are Phase, Apogee and Perigee, Node and Libration chapters for the Moon. Solar observers can use the chapter on heliographic coordinates, based on Carrington's rotation number, to plot and track sunspots. For eclipses, Meeus gives us a chapter that, with relatively modest calculations, predicts the time, magnitude and duration for lunar and solar eclipses with remarkable accuracy. There is even a chapter on how to construct a planar sundial. Even Pluto, which is calculated in astrometric place, has a chapter.

You will not see the usual vector / matrix notation, the actual equations are provided for us instead. Throughout the book, definitions are given for the astronomical terms, each of which is summarized in the glossary. Beginning with the chapter on Accuracy, he consistently reminds us what constitutes significant digits and why rigorous expressions are often not necessary. For example, there are alternative, low precision algorithms which are quite accurate and provide a good starting point for learning the concepts.

This reviewer has coded most of the algorithms in the book and generated very accurate geocentric and topocentric apparent place ephemerides for the Sun, Moon, planets and the Galilean satellites.

A knowledge of plane and spherical trigonometry along with basic algebra and calculus is recommended, but the programming inclined should find rewarding challenges in translating these algorithms into computer programs and begin creating their own ephemerides.

The reviewer has a B.S. in geophysics and is currently a C++ programmer.