GPS for Dummies.pdf - Engineering Surveyor

IntroductionAs you may have guessed from the title, this book is about GPS (thesatellite-based Global Positioning System) and maps; digital mapsto be exact.I remember back in 1989 when Magellan introduced the first handheld GPSreceiver, 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 twopounds. It was single channel receiver, could only track four satellites, andjust supported latitude and longitude coordinates. It could save 100 waypointsand 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 sportinggoods store and buy a GPS receiver smaller than a small cell phone. It weighsa couple of ounces, can track up to 12 satellites, and on a good day tells meexactly where I’m located to within about 10 feet; and in several differentcoordinate systems by the way. It supports 500 waypoints and 20 routes, with125 waypoints apiece. Best of all it costs around $100.Maps have followed the same evolutionary path. Paper maps have turneddigital and now you can visit a Web site and print out a map with drivingdirections to just about anywhere for free. For under $100 you can buy mappingsoftware that has a collection of CD-ROMs with detailed topographicmaps that fully cover any state in the United States. Aerial photographs arereadily available over the Internet, and stunning three-dimensional maps canbe created with a few mouse clicks. Once the exclusive domain of professionalcartographers and GIS (Geographic Information System) specialists,the average computer user can create and use digital maps with relative ease.There are a number of free and inexpensive programs that make desktopmapping a reality for the rest of us.So, does all this mean we’re entering the dawn of a new era where no matterwhere you are it’s going to be hard to get lost? Well, yes and no.