The project that led to this text began in a conversation with Jack Dangermond of ESRI in May of 1993. I proposed to quickly put together a short introduction to GPS for GIS users. Since that time I have learned a great deal about both GPS and “quickly putting together a short introduction.” Several software releases later, several introductions of GPS hardware later, and many occasions on which I learned that there was a lot more to this subject than I imagined, it is finished. I could not have done it without:
My daughter Heather Kennedy, who gave great help and support along the way and, particularly, who did the painstaking and intense work of final proofing and testing.
My son Evan Kennedy, who added to the collection of GPS tracks presented in the text by taking a GPS receiver across the United States by automobile, and whose enthusiasm for GPS encouraged me to complete the book.
Allan Hetzel, who took on the job of fixing and printing the camera-ready copy. He coped with corrections from several reviewers and coordinated the final marathon production session.
Dick Gilbreath, who, with the help and forbearance of Donna Gilbreath, spent many hours at inconvenient times producing most of the figures, and who insisted on getting the smallest details right.
Yu Luo and Pricilla Gotsick of Morehead State University, who burned the CD-ROM used for the data in the First Edition.
People at ESRI: Jack Dangermond, who supported the idea of this text. Bill Miller, Earl Nordstrand, and Michael Phoenix, who provided encouragement and advice.
People at Trimble Navigation: Art Lange, my GPS guru, who provided considerable technical help and kept me from making several real blunders. Chuck Gilbert, Chris Ralston, and Dana Woodward, who helped by providing advice and equipment.
Michele Vasquez, who provided photos for the text.
Michele Carr, of AST Research, for the use of the pen computer that facilitated GPS data collection.
Carla Koford and Ethan Bond of the GIS lab at the University of Kentucky (UK), who tested and corrected procedures and text, and
Jena King, who read and improved parts of the text.
Justin Stodola, who wrote the “C” program and the procedures for digitizing coverages directly into unique UTM tiles.
People who collected GPS data in faraway places: Will Holmes for the Mexican data and Chad Staddon, who took a GPS receiver to Bulgaria.
Bob Crovo, of the UK computing center, who was always cheerful about answering dumb questions.
Ron Householder of MapSync, and Tim Poindexter of CDP Engineers, who use GPS as professionals and know a lot that isn’t in the manuals.
David Lucas, GIS coordinator for Lexington–Fayette County, who guided me through some sticky problems with UNIX and license managers and provided data on Lexington Roads.
Ken Bates–Mr. GIS for the state government of Kentucky–and Kent Annis of the Bluegrass Area Development District, for their help and insights.
The students in several classes of GEO 409, 506, and 509–GIS and computer-assisted cartography courses at UK–who read the book and tested the exercises.
Ruth Rowles, who used an early version of the text in her GIS class at UK.
Calvin Liu, who operates the GPS community base station at UK and provided many of the base station files used herein. And the folks at the base station in Whiterock, B.C. for helping a stranger with an urgent request.
Scott Samson, who provided good advice at important times.
Jon Goss and Matt McGranaghan, who facilitated my stay and lecture at the University of Hawaii–one of the nicer places to collect GPS data, or data of any sort for that matter.
Tom Poiker, of Simon Fraser University, for his help and counsel on various GIS topics, and to him and Jutta for their hospitality in their home in British Columbia–also a great place for data collection.
Max Huff, of OMNISTAR, Inc., who demystified the complex
“differential corrections anywhere” system and provided hardware for same.
Several companies for hardware, software, and support: ESRI for sponsoring the project and providing software; Trimble Navigation, for providing the GPS hardware; AST Research, for use of a pen computer for collecting data while traveling; and AccuPoint and OMNISTAR for access to their differential correction services.
John Bossler, of Ohio State University, who does really hi-tech GPS, and who was patient in letting me finish this text, delaying a project I was doing for him.
Hans Vinje, First Officer of the Nordic Empress, who took the time to explain the way ship navigators combine GPS with other navigational systems, and to Captain Ulf Svensson, who invited me to spend time on the bridge.
The folks at Ann Arbor Press, who did indeed “press” to get the book into final form: Skip DeWall and Sharon Ray. I should add that responsibil ity for the appearance of the text and any errors you may find rest entirely with the author. While I received considerable help in development of the material, I provided the camera-ready text and was responsible for the correctness and format of the final work.
My colleagues in the Department of Geography at UK–and particularly to Richard Ulack, its chair–who indulged my absences and absent-mindedness during the last weeks of this project.
And finally my dear friend Barb Emler, who repairs children’s teeth from nine to five every day and justly believes that people ought to enjoy life without work outside of those times. She’s right.
And I will. For a while, anyway.
Further
In putting together the second edition, which for some reason was no less work than the first, I am very indebted to:
Dr. Thomas Meyer, Assistant Professor in the Department of Natural Resources Management and Engineering at the University of Connecticut, who used the text in his classes, and commented on several chapters of the text which kept me from making major mistakes in the area of geodesy.
Dr. Kenneth L.Russell, Professor at Houston Community College, who inflicted draft versions of the text on his students and carefully detailed the ways in which the text worked, and didn’t
work. His real-world experiences with GPS and GIS were immensely helpful.
Dr. Qinhua Zhang, who carefully read and tested the entire text.
He painstakingly went through every word and every exercise–
saving me (and you, the reader) from enduring many minor errors and a couple of major mistakes.
James Long, who kept my computing equipment humming, or at least running, despite hardware and operating system frustrations.
Teresa Di Gioia, for carefully testing two chapters.
Janice Kelly and Cooper Gillis for their hospitality in Newport, Rhode Island, which served as a base for data collection in New England.
Pat Seybold, for her encouragement and assistance with development of an exercise illustrating differential correction.
More people who collected GPS data in faraway places: Dr. Paul Karan for the data from Japan, and Jennifer Webster for data from Ecuador.
Terrapro in British Columbia, Canada for differential correction files.
And some more of the helpful people at Trimble Navigation, Limited: Art Lange, as usual.
Greg May, formerly of the Geo3 team, presently involved in Trimble’s precision agriculture projects, who analyzed data and answered numerous questions (after 40 E-mails and a dozen phone calls, I quit counting) on all facets of GPS,
Pat McLarin, Geo3 Product Manager, who helped me understand how the Geo3 is different.
Fay Davis, Pathfinder Office Product Manager, who persevered through my constant barrage of “why doesn’t the software do such and such” questions.
Alan Townsend, for writing the Foreword to the Second Edition.
And Allison Walls, Andrew Harrington, Brian Gibert, Barbara Brown, Chris Ralston, Erik Sogge, Bob Morris, Paul Drummond, Neil Briggs for important help with the myriad of little issues that crop up in writing a technical text.
And finally to Lynne Johnson and Amy Hockey from Ann Arbor Press, for their amazing patience and perseverance, not to mention great talent.
ArcView and ArcInfo Graphical User Interface are the intellectual property of ESRI and are used herein with permission.
Copyright © 1996—2001 ESRI. All rights reserved.
GPS Pathfinder Office Graphical User Interface is the intellectual property of Trimble Ltd. and is used herein with permission. Copyright © 1997—2001 Trimble Ltd. All rights reserved.
INTRODUCTION
Two of the most exciting and effective technical developments to emerge fully in the last decade are:
• the development and deployment of Global Positioning Systems (the GPS of the United States is called NAVSTAR), and
• the phenomenon of the Geographic Information System (GIS).
GIS is an extremely broad and complex field, concerned with the use of computers to input, store, retrieve, analyze, and display geographic information. Basically GIS programs make a computer think it’s a map–a map with wonderful powers to process spatial information, and to tell its users about any part of the world, at almost any level of detail.
While GPS is also an extremely complex system, using it for navigation is simple by comparison. It allows you to know where you are by consulting a radio receiver. The accuracies range from as good as a few millimeters to somewhere around 15 meters, depending on equipment and procedures applied to the process of data collection.
More advanced GPS receivers can also record location data for transfer to computer memory, so GPS can not only tell you where you are–but also tell you where you were. Thus, GPS can serve as means of data input for GISs. This subject is not quite a simple as using GPS for navigation. Traditionally (if one can use that word for such a new and fast moving technology), GISs got their data from maps and aerial photos. These were either scanned by some automated means or, more usually, digitized manually using a handheld “puck” to trace map features–the map being placed on an electronic drafting board called a “digitizer.” With GPS, the earth’s surface becomes the digitizer board; the GPS receiver antenna becomes the puck. This approach inverts the entire
traditional process of GIS data collection: spatial data come directly from the environment and the map becomes a document of output rather than input.
A cautionary note: The aim of this text is to teach you to use GPS as a source of input to GIS. The book is somewhat unusual in that it has multiple characteristics: It is an informational discussion, a manual, and a workbook. What I try to do is present material in a way and in an order so you can gain both obvious and subtle knowledge from it if you are paying close attention. For each major subject there is an Overview followed by Step-by-Step procedures. After each step you should think about what the step implies and what you could learn from it. As with many tutorials, it may be possible, in the early parts of the text, to go through the steps sort of blindly, getting the proper results but not really understanding the lessons they teach. I advise against that.
Positioning System and GIS:
An Introduction Second Edition