GPS for Dummies.pdf - Engineering Surveyor

172Part III: Digital Mapping on Your ComputerGetting maps to GPS receiversAll GPS manufacturer map programs upload maps to your GPS receiver insimilar ways. Although the user interfaces are different and the commandsvary, you load a map onto a GPS receiver by using the same basic process.1. Run the map program and zoom in on the area that you want toupload to your GPS receiver.2. Choose which parts of the map you want to upload to the GPSreceiver.This usually means selecting one or more rectangular areas on the map.Depending on the program, you either draw a rectangle that defines theareas that you want to upload, or you select grid squares that appear onthe map that correspond to the areas you want to upload.3. Connect your GPS receiver to your PC.You use a special cable for this data transfer connection. To read moreon connecting your GPS receiver to a PC, go to Chapter 9.If the GPS receiver uses a memory card to store maps, you can skip thisstep.4. Set the communications parameters in the map program.This comprises the COM port, baud rate, and other settings that areneeded so that the GPS receiver can successfully communicate with yourPC. (Read how to do this in Chapter 9.) This is usually a one-time setup,so you don’t need to repeat this each time you want to upload a map.Again, you can skip this step if your GPS receiver uses a memory card.5. Upload the map to your GPS receiver.The program extracts the information that it needs from the map dataCD-ROM and builds a custom map of the area that you select. When thisprocess finishes, the program either starts uploading the map to the GPSreceiver or saves the map to your hard drive where you can copy it to amemory card (if applicable).How long building a map takes depends on the size of the area that youselect, how much map detail you want to include, and how fast your PC is.This can range from a minute or less for small areas (such as a metropolitanarea) to five or ten minutes for a large map (such as one that includes manydifferent states). For example, when using Lowrance’s MapCreate, it takes alittle under five minutes to create a 26MB map of the state of Oklahoma andthe Texas panhandle on a typical PC that’s been manufactured within thepast several years.How much time it takes to upload a map into a GPS receiver also depends onthe size of the area you select and how the receiver stores maps. If you’re