GPS For Dummies, 2nd Edition®

Table of Contents


Who This Book Is For

Setting Some GPS Expectations

How This Book Is Organized

Part I: All About Digital Maps

Part II: All About GPS

Part III: Digital Mapping on Your Computer

Part IV: Using Web-Hosted Mapping Services

Part V: The Part of Tens

Icons Used in This Book

Some Opening Thoughts

Part I: All About Digital Maps

Chapter 1: Getting Started with Digital Maps

Amerigo Vespucci Didn’t Have Maps like This

Static map

Smart map

Mapping Programs

Consumer programs

GIS (Geographic Information System) programs

Consumer versus GIS programs

Digital Maps in Practice

Mapping Software: The Essentials

Standalone programs

Programs with bundled maps

Web-hosted mapping services

Chapter 2: Dissecting Maps

Discovering Types of Maps




Figuring Out Map Projections

Map Datums

Working with Map Coordinate Systems


Universal Transverse Mercator (UTM)

Township and Range

Measuring Map Scales

Deciphering Map Symbols

Digital Map Data


Digital Line Graph (DLG)

Elevation data

Digital Raster Graphics (DRG)

Digital Orthophoto Quadrangle (DOQ)

Satellite data

Part II: All About GPS

Chapter 3: GPS Fundamentals

Global Position What?

GPS Deconstructed

Eyeing satellites

GPS radio signals

Covering ground stations

GPS receivers

GPS receiver accuracy

Stuff Your GPS Receiver Can Tell You

GPS Receiver Features


Display and output


Built-in maps

Enhanced accuracy


Internal storage

External storage

User interfaces

Accessory software

Accessory hardware

The Future of GPS

Chapter 4: Grasping Important GPS Concepts

Linking GPS, Maps, and Coordinate Systems

Dealing with Datums

Setting Waypoints

Saving waypoints

Using the waypoint list

Following Routes

Making Tracks

Chapter 5: Selecting and Getting Started with a Handheld GPS Receiver

Selecting a Handheld GPS Receiver

To map or not to map

GPS for athletes

Matching GPS receiver features to your activities

Becoming Familiar with Your New GPS Receiver

Powering Your GPS Receiver

Battery basics

Power to the people

Initializing Your GPS Receiver

Changing Receiver Settings

Using Your GPS Receiver

Coming home

How far, how fast?

Finding your ancestors

Simulating navigation

Homework assignment

And more . . .

Chapter 6: Automotive GPS Receivers

Automotive GPS Receiver Features

Street map

Routing directions


Address books

Trip Log



Entertainment features


Subscription services

Voice recognition

Types of Automotive GPS Receivers

Portable navigators

In-dash navigators

Selecting an Automotive GPS Receiver

Using Your Automotive GPS Receiver

First things first

Mounting options

On the road

Updating maps and firmware

Homework assignment

Chapter 7: Cellphones, PDAs, and Other GPS Devices

GPS and Cellphones

Cellphones and Assisted GPS (A-GPS)

Bluetooth cellphones and GPS

Non-GPS cellphone navigation

Location-based services

Cellphones versus dedicated GPS units

GPS and PDAs

Choosing between a handheld GPS receiver and a PDA

Interfacing your PDA to a GPS receiver

Reviewing PDA mapping software

GPS Trackers

People trackers

Pet trackers

Vehicle and vessel trackers

GPS Data Loggers

GPS Radios

FRS radios

Ham radios

Marine radios

Chapter 8: Geocaching

Geocaching: The High-Tech Scavenger Hunt

Getting Started Geocaching

What you need to geocache

Selecting a cache to look for

Finding the cache

GeoJargon: Speaking the lingo

Hiding a Cache

Selecting a container

Location is everything

Stocking the cache

Submitting the cache

Maintaining the cache

Geocaching Etiquette

Internet Geocaching Resources

Part III: Digital Mapping on Your Computer

Chapter 9: Digital Mapping Hardware Considerations

Digital Mapping Software Choices

Processing Power



Storage Capacity

Hard drives

CD and DVD drives

Display Equipment

Graphics cards



Communication Capabilities

Communication ports

Internet connection

Chapter 10: Interfacing a GPS Receiver to a Computer

About (Inter)Face: Connectivity Rules

Anatomy of a Link: Understanding the Interface Process

Untangling Cables

Pondering Protocols

Understanding Serial Ports

COM ports

All About USB Ports

Virtual serial ports

USB serial port adapters

Managing Memory

Transferring GPS Data

Troubleshooting Connection Problems

Uploading Firmware Revisions to Your GPS Receiver

Chapter 11: Using GPS Manufacturer Software

Understanding GPS Map Software

Some GPS map software rules of thumb

Common GPS map software features

Getting GPS maps

Loading maps to GPS receivers

Exploring Garmin Software


Garmin map products

Garmin utility programs

Scouting Magellan Software


National Geographic TOPO!

Magellan map products

Discovering Lowrance Software

Navigating DeLorme Software

Chapter 12: Finding Places and Coordinates

Finding Your Way with Online Gazetteers

Using the Geographic Names Information System (GNIS)

Using the GEOnet Name Server (GNS)

Converting Coordinates

Using GeoTrans

Using online conversion utilities

Chapter 13: On the Road with DeLorme Street Atlas USA

Discovering Street Atlas USA Features

Navigating Street Atlas USA

Exploring the Street Atlas USA interface

Zooming in and out

Moving around in Street Atlas USA

Getting POI information

Finding an Address with Street Atlas USA

Getting from Here to There with Street Atlas USA

Creating a route

Getting directions

Printing and saving directions

Moving Maps with Earthmate

Other Street Navigation Software

Microsoft Streets & Trips

Garmin Mobile PC

Chapter 14: On the Ground with TopoFusion

Discovering TopoFusion

Displaying Maps and Finding Places

Navigating a TopoFusion Map

Changing the map type

Moving around in a map

Changing the map size

Planning a Trip with TopoFusion

Understanding Terrain Elevation

Displaying a 3-D map

Charting elevation profiles

Blending maps and aerial photos

Reviewing Other Topographic Map Software

DeLorme Topo USA

Maptech Terrain Navigator

National Geographic TOPO!

Chapter 15: From the Sky with Google Earth

Discovering Google Earth

Traveling the Globe

Navigation controls

Zooming in and out

Moving around

Finding places

Getting a 3-D View

Using Layers

Available layers

Turning layers on and off

Adding Placemarks

Measuring Distances

Chapter 16: Creating and Using Digital Maps with OziExplorer

Discovering OziExplorer Features

Moving from Paper to Digital Maps

Step 1: Scan the map

Step 2: Edit the map

Step 3: Calibrate the map

Checking your work

Part IV: Using Web-Hosted Mapping Services

Chapter 17: Saving and Editing Web Maps

Saving Maps

Save Picture As

Using the Print Screen key

Using screen capture programs

Editing a Map

Opening a file


Using colors and fonts

Adding symbols

Selecting the right file format

Chapter 18: Navigating Web Road Maps

Using Street Map Web Sites

Listing common street map Web site features

Web versus PC software street maps

Reviewing Street Map Web Sites


Google Maps

Yahoo! Maps

Live Search Maps

Chapter 19: Exploring Web Topographic Maps

Using Web-Hosted Topographic Maps

Advantages of topographic Web sites

Disadvantages of topographic Web sites

Deciding between Web-based maps and mapping programs

Reviewing Topographic Map Web Sites

Using TerraServer-USA

Using GPS Visualizer

Commercial topographic Web map sites

Part V: The Part of Tens

Chapter 20: Ten Great GPS and Map Web Sites

Comprehensive GPS Information

Current GPS News and Helpful Advice

Technical GPS Information

Free Maps

Expert Desktop Mapping Guidance

Definitive Terrain Modeling Information

Chapter 21: Ten Map Printing Tips

Make Your Paper Count

Print in Color

Print the Scale

Print UTM Grids

Use Waterproof Paper

Waterproof Your Plain Paper

Print More Map Area

Put North at the Top

Use the Best Page Orientation

Beware of False Economy

Chapter 2 2: Ten GPS Resources for Boaters

Free Charts to Download

Free Windows Navigation Software

Commercial Navigation Software

Marine GPS and Chart Plotter Manufacturers

GPS and Marine Electronics Blogs

Marine Electronics Forums

Cruising Wikis

Nautical Chart Overlays for Google Earth

Keeping Your Handheld GPS Unit off the Bottom

Free Tide Software

GPS For Dummies 2nd Edition


About the Author

Joel McNamara first got involved with digital maps in the early 1980s. At the time he was studying archeology and instead of going out and playing Indiana Jones, he found himself in front of a computer monitor trying to predict where archeological sites were located based on LANDSAT satellite data.

The lure of computers ultimately led to his defection from academia to the software industry, where he worked as a programmer, technical writer, and manager; eventually ending up at a rather large software company based in Redmond, Washington. Joel now writes and consults on technology he finds interesting, such as GPS and digital maps.

Over the years he’s had practical experience using GPS and maps for wildland firefighting, search and rescue, and disaster response and planning. He’s also an avid user of the great outdoors (which means there’s way too much gear in his garage). He likes boats of all kinds and is fond of certain old-school, dinosaur technologies such as celestial navigation.

Joel is also the author of Geocaching For Dummies, Secrets of Computer Espionage: Tactics & Countermeasures, and Asus Eee PC For Dummies (all published by Wiley).

Author’s Acknowledgments

Once again, thanks to my wife, Darcy, for all her support during my work on this book; especially for the patience in putting up with all of the maps, CD-ROMs, cables, manuals, and gadgets that were scattered all over the house.

Next on the list are the folks at Wiley, including Katie Feltman, my acquisitions editor at Wiley, who was happy with the first edition of this book and asked me to update it. Mark Enochs, project editor extraordinaire, ably kept the book on course. And Dan Kearl, a savvy search and rescue/disaster response colleague, GPS instructor, and all-around techie who kept me honest as my technical editor. (A note of appreciation to Pat O’Brien, project editor, and GPS and map guru Gavin Hoban, technical editor, for all the work they did on the first edition.)

I’d also like to thank the following manufacturers for supplying review copies of their products to write about in the first and second editions: DeLorme (Caleb Mason and Charlie Conley), Endless Pursuit, Lowrance (Steve Wegrzyn), Magellan, Maptech, Microsoft, National Geographic, and TopoFusion (Scott Morris). I’m especially grateful for the help from the folks named in the parentheses who went above and beyond the call of duty in answering questions and providing assistance.

Finally, thanks to everyone who gave me feedback on various parts of this edition and the previous one. You know who you are, and I appreciate it.

Publisher’s Acknowledgments

We’re proud of this book; please send us your comments through our online registration form located at

Some of the people who helped bring this book to market include the following:

Acquisitions and Editorial

Senior Project Editor: Mark Enochs

Senior Acquisitions Editor: Katie Feltman

Copy Editor: Brian Walls

Technical Editor: Dan Kearl

Editorial Manager: Leah Cameron

Editorial Assistant: Amanda Foxworth

Sr. Editorial Assistant: Cherie Case

Cartoons: Rich Tennant (

Composition Services

Project Coordinator: Erin Smith

Layout and Graphics: Reuben W. Davis, Melissa K. Jester, Christin Swinford, Christine Williams

Proofreaders: Christine Sabooni, Amanda Steiner

Indexer: Claudia Bourbeau

Publishing and Editorial for Technology Dummies

Richard Swadley, Vice President and Executive Group Publisher

Andy Cummings, Vice President and Publisher

Mary Bednarek, Executive Acquisitions Director

Mary C. Corder, Editorial Director

Publishing for Consumer Dummies

Diane Graves Steele, Vice President and Publisher

Composition Services

Gerry Fahey, Vice President of Production Services

Debbie Stailey, Director of Composition Services


You may have guessed from the title that this book is about GPS (the satellite-based Global Positioning System) and maps (digital maps to be exact).

I remember back in 1989 when Magellan introduced the first handheld GPS receiver, the NAV 1000. (Don’t worry. This isn’t going to be one of those “I used to walk 20 miles to school in the snow when I was your age,” stories.) The NAV 1000 was the size of a brick, and weighed a little less than two pounds. It was a single channel receiver, could only track four satellites, and supported only latitude and longitude coordinates. It could save 100 waypoints, and you could have a single route with up to 10 waypoints. It cost $2,500.

Fast-forward to the present: Now I can go down to my neighborhood sporting goods or electronics store and buy a GPS receiver the size of a small cellphone. It weighs a couple of ounces, can track three to four times as many satellites, and on a good day can tell me exactly where I’m located to within about 10 feet; and in several different coordinate systems, by the way. It supports at least 500 waypoints and 20 routes, with 125 waypoints apiece. Best of all, it costs around $100. And, for not too much more, I can get an automotive GPS receiver that tells me aloud how to get where I’m going. It’s like living in the future.

Maps have followed the same evolutionary path. Paper maps have turned digital, and now you can visit a Web site and print a map with driving directions to just about anywhere for free. For under $100, you can buy mapping software that has a collection of CD-ROMs with detailed topographic maps that fully cover any state in the United States. Aerial and satellite photographs are readily available over the Internet, and stunning three-dimensional maps can be created with a few mouse clicks. Once the exclusive domain of professional cartographers and GIS (Geographic Information System) specialists, the average computer user can create and use digital maps with relative ease. A number of free and inexpensive programs make desktop mapping a reality for the rest of us.

So does all this mean we’re entering the dawn of a new era where no matter where you are it’s going to be hard to get lost? Well, yes and no.

Over the past several years, GPS receivers have become extremely popular and affordable. Lots of people who venture away from urban areas are carrying them. Cars come installed with GPS navigation systems for negotiating city streets and highways. Many cellphones have tiny GPS chips embedded in them. And, even if you don’t have a GPS receiver, you can always go out on the Web and print a map of where you want to go. But, there are a few hitches in this perfect, always-found world:

GPS receivers often boast so many features it’s easy to get lost trying to figure them all out. Plus, most GPS receiver owners typically use only a small subset of the available features (and sometimes don’t even know how to use these features well enough to avoid getting lost).

GPS receivers have capabilities and limitations that many owners (or potential owners) really don’t understand. This leads to frustration or not being able to use the devices to their full potential.

Digital street map data displayed and used by GPS receivers is often updated (especially in areas experiencing lots of growth).

Although many people have a general knowledge of how to read a map, at least the simple road variety, most don’t know how to really maximize using a map.

And finally, the average computer user isn’t aware of the wealth of easy-to-use, free or inexpensive mapping resources he could be using to stay found.

The purpose of this book is to help you better understand and use GPS receivers and open your eyes to the world of digital mapping — and, I hope, put you on the path of always staying found or finding what you’re looking for.

Who This Book Is For

If you’re browsing through this book at your favorite bookstore right now, and are pondering whether to take it to the cashier, ask yourself these questions:

Are you considering purchasing a GPS receiver?

Have you recently purchased a GPS receiver (or got one as a gift)?

Have you owned a GPS receiver for a while, but want to get more from it?

Are you interested in using digital maps for your profession or hobby?

If you answered yes to any of these questions, then stop reading and immediately proceed to the cash register because this book will make your life easier (if you’re still not convinced, feel free to continue flipping through the pages to see what I mean).

Getting a bit more specific, people in the following groups should find this book especially useful:

Recreation – Hikers, hunters, fishers, mountain bikers, trail runners, cross-country skiers, snowshoers, snowmobilers, prospectors, pilots, boaters, geocachers, and anyone else who ventures outdoors away from cities and streets (with or without a GPS receiver).

Transporation – Drivers of all types of motorized vehicles (cars, trucks, motorcycles, you name it) are increasingly becoming dependent on GPS to help them navigate highways, byways, and even off-road.

Commercial – Land developers and real estate agents who are interested in the competitive advantage maps can bring them for planning or marketing purposes.

Government – Emergency response agencies (search and rescue, fire, law enforcement, disaster relief) and urban planners who use maps as part of their planning and response activities.

Environmental – Conservation agencies, organizations, consultants, and scientists (biologists, botanists, and other ists) who use maps for resource management and research.

Technology – Anyone who likes to play with cool technology.

You may have noticed I didn’t mention people like surveyors or GIS professionals. If your job primarily focuses on GPS and/or maps, you’ll probably discover a few things in the following pages, but just remember that this book is for the average computer user and GPS receiver owner who don’t have your level of technical experience, proficiency, and skills. Please don’t expect to find the nuts and bolts of using GIS software or precision surveying electronics.

And finally, if you purchased the first edition of GPS For Dummies (thank you very much), you’ll find I’ve made a number of updates and added a lot of new information to stay current with the latest in GPS and digital mapping products and services.

Setting Some GPS Expectations

Before getting started, I want to set a few expectations about the content you’ll be reading about that relates to GPS receivers, just so we’re all on the same page:

This book focuses on handheld, consumer GPS receivers (typically used for land navigation) and automotive navigation systems. In addition to these types of GPS receivers, larger and less portable models are used in airplanes, boats, and commercial vehicles. The U.S. government and military uses restricted-use GPS units, and expensive receivers are used for surveying. Although some of these GPS receivers are discussed briefly, don’t expect to find out as much about them as the land and auto consumer models.

Although most GPS receivers have the same general functionality, there are a lot of differences in manufacturer and model user interfaces. In a way, it’s like sitting a computer novice in front of three PCs, one running Microsoft Windows, one running Linux (with the KDE or Gnome interface), and the other a Macintosh, and then asking the volunteer to perform an identical set of tasks on each computer. Good luck! Because of the differences, you’re not going to find detailed instructions on how to use specific GPS receiver models. What you will find is information on how to use most any GPS receiver, with some kindly suggestions tossed in when it’s appropriate to consult your user guide for details.

Finally, don’t expect me to tell you what the best GPS receiver is. Like any consumer electronics product, GPS receiver models are constantly changing and being updated. Instead of recommending that you buy a certain brand or model (that could possibly be replaced by something cheaper and better over the course of a few months), I tell you what questions to ask when selecting a GPS receiver and give you some hints on which features are best for different activities. You can apply these questions and selection criteria to pretty much any GPS receiver (no matter how much the marketplace changes) to pick the right model for you.

Take comfort in the fact that it’s pretty hard to go wrong when you purchase a GPS receiver from one of the brand-name manufacturers who specialize in GPS (Garmin, Magellan, Lowrance, and TomTom to name a few of the bigger players). All these companies make excellent products, and you can expect to get a number of years use from them. (The good news is that GPS technology and product features haven’t changed as rapidly as personal computers. I can go out and happily use a GPS receiver from 1998, whereas the same vintage personal computer would have been recycled long ago. It may not lock on to satellites as fast or have as many new whiz-bang features, but it still tells me where I’m at.)

How This Book Is Organized

This book is conveniently divided into several different parts. The content in each part tends to be related, but feel free to skip around and read about what interests you the most.

Part I: All About Digital Maps

This part of the book introduces you to digital maps; actually, it presents some important universal concepts that apply to both paper and digital maps, such as coordinate systems, datums, and how to read and use maps. The focus is primarily on land maps but there are a few brief mentions of nautical and aeronautical charts. In this part, you find out about different types of digital maps that are available, especially the free ones you can get from the Internet, and about some of the software you can use for digital mapping.

Part II: All About GPS

This is the part of the book devoted to demystifying GPS and GPS receivers. You find out about the technology behind GPS (including its capabilities and limitations), basic GPS concepts (such as waypoints, routes, tracks, and coordinate systems), and how to select and use a handheld and automotive GPS receiver. I tell you all about GPS cellphones, PDAs (like Pocket PCs and Palms), trackers, and other devices, and a bit on the popular GPS sport of geocaching.

Part III: Digital Mapping on Your Computer

In this part, I take some of the theoretical information on digital maps from Part I, and get practical. This section discusses computer requirements needed for basic digital mapping and reviews a number of different software packages you can use to work with aerial photos, topographic maps, and road maps. Many of these programs support uploading and downloading data to and from GPS receivers, so I also spend some time talking about how to interface a GPS receiver to a personal computer.

Part IV: Using Web-Hosted Mapping Services

Even if you don’t have a GPS receiver or mapping software installed on your computer, with an Internet connection and a Web browser you can still do a remarkable amount of digital mapping with free and subscription Web services. This section discusses how to access and use online street maps, topographic maps, aerial photos, and some slick U.S. government-produced maps. You also discover how to save and edit these Web-based maps.

Part V: The Part of Tens

All For Dummies books have a part called The Part of Tens, and this one is no exception. In this section, you find lists of what I consider the best GPS and digital map Web sites on the Internet, where to find free digital maps, and tips and hints on printing maps. And, if you’re a boater, there’s a lockerfull of marine GPS resources.

Icons Used in This Book

Maps use symbols to convey information quickly, and this book does the same by using icons to help you navigate your way.

remember.epsJust a gentle little reminder about something of importance, and because I can’t be there to mention it in person and give you a friendly (and stern if needed) look while wagging my finger, this icon will have to do.

technicalstuff.eps I try to keep the real geeky, nerdy things to a bare minimum, but because this is a book about cool electronic gadgets and computer mapping, sometimes the technical stuff does creep in. I either give you a plain-English explanation or point you to a Web site where you can get additional details.

Tip.eps This is good stuff designed to make your life easier; usually gained from practical experience and typically not found in manufacturer user guides and product documentation; or if it is there, it’s buried in some obscure paragraph.

Warning(bomb).eps The little bomb icon looks as if it should signify some pretty bad juju, but in reality it could represent something as minor as potentially causes a hangnail. The key here is to pay attention because there might be something lurking that causes mental, physical, emotional, or monetary suffering of some degree. Who would have thought reading GPS For Dummies could be an extreme sport?

Some Opening Thoughts

Before you jump into the exciting world of GPS and digital maps (I know you can’t wait), I want to mention a few final thoughts:

There are lots of references to Web sites in this book. Unfortunately, Web sites change just about as fast as street maps in a city experiencing a lot of growth. If for some reason a link doesn’t work, you should have enough information to find what you’re looking for by using common sense and a search engine, such as Google.

You’re not going to find every GPS and map software title in existence mentioned in the book. I try to list and describe many of the more popular programs, but the realities of page count constraints prevents this book from turning into an encyclopedia. So please don’t get upset if I don’t mention a program you use or you feel slighted because I end up talking about one program more than another.

On some occasions while you’re reading this book, you’re probably going to think I sound like a broken record on one point I feel is very important. If you venture away from civilization with your GPS receiver, please bring a compass and a paper map with you, and know how to use them. That means really knowing how to use them, not just kidding yourself that you do. From many years of doing search and rescue work and finding lost people, I’ve discovered the following truths:

• GPS receiver batteries die at the most inopportune time; especially when you didn’t bring spare batteries with you.

• If a GPS receiver breaks or gets lost, it will do so at the worst possible moment.

• GPS receivers are not Star Trek teleporters that will instantly transport you out of the wilderness and trouble (this is also true when it comes to cellphones).

All the information in this book should set you on your way to becoming an expert with a GPS receiver and maps. That is, if you practice! If you want to have guru status, you need to be applying what you discover in this book. Even if you don’t aspire to becoming one with GPS and a master of maps, to get the most use from your navigation tools, you need to become both comfortable and confident with them. Discover, experiment, and have fun!

Par t I

All About Digital Maps


In this part . . .

Although digital maps are made of bits and bytes, they share a number of things in common with their paper and ink cousins — like datums, coordinates systems, scales, legends, and compass roses. In fact, when you get some of these concepts down, you’ll be at home with just about any map you encounter, whether it’s displayed on your PC’s monitor or laying on the front seat of your car.

Paper maps have a certain old school charm, but digital maps are infinitely cooler. That’s because you can associate data with a digital map and make it interactive and smart. This part sets the stage for other chapters in the book. We’re going to be talking about all sorts of PC, Web-based, and GPS maps, and it’s important that you understand the basics of how digital maps work and what types of digital maps are out there; especially the free ones available on the Internet.