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Geographic information systems (GIS) - a central repository of geographic data collected from various sources, including satellites and GPS is emerging as one of the most intriguing and promising high-tech fields. Today, many technical, managerial, engineering, and academic positions require GIS skills, and this easy-to-understand resource answers the call. The book examines and explains all of the critical GIS concepts in a clear voice and in a consistent structure. It provides technical and non-technical professionals, regardless of their background, with an accessible and practical guide to important GIS know-how. While other GIS-learning sources are software-product biased, this unique volume offers an unbiased approach to the fundamentals of learning GIS, helping the reader become functional and knowledgeable in this burgeoning area.
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Geographic Information Systems Demystified For a listing of recent titles in the Artech House Mobile Communications Series, turn to the back of this book. Geographic Information Systems Demystified Stephen R. Galati artechhouse.com Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the U.S. Library of Congress. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. ISBN-10: 1-58053-533-x ISBN-13: 978-1-58053-533-5 Cover design by Robert Pike © 2006 ARTECH HOUSE, INC. 685 Canton Street Norwood, MA 02062 All rights reserved. Printed and bound in the United States of America. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Artech House cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. 10 9 8 7 6 5 4 3 2 1 To my wife Janet and my children, Zachary, Nicholas, Sarah, and Jacob Contents xv Preface 1 2 Acknowledgments xvii Introduction xix Part I: What Is a Geographic Information System? 1 How Does a GIS Work? 3 The Fundamental Flow of Information 3 Geography and Geographic Data 5 Georeferencing 8 Queries: Locations and Attributes 8 Geoprocessing 9 Spatial Analysis 11 Geographic Information 12 Why Use a GIS? 15 Discerning Your Need for GIS 16 vii viii Geographic Information Systems Demystified 3 4 Common GIS Products and Bi-Products 17 Database Management Systems 19 Quality Assurance, Six Sigma, and GIS 25 Project Visibility and Popularity 26 Benefits, Cost Savings, and Automation 27 The Structure of Geographic Data 29 Raster and Vector Data Structures 29 Vector Feature Geometry 31 Raster Image Structures 34 Topology 35 GIS Attribute Tables and Indices 38 Geospatial Metadata 41 What Is Metadata? 42 Geospatial Metadata and GIS 43 Metadata Schemata, Element Sets, and Syntax 45 Geospatial Metadata Standards 48 Content Standards for Digital Geospatial Metadata Dublin Core Meta