GPS for Dummies.pdf - Engineering Surveyor

Chapter 6: Using GPS with a PDA109You can’t talk about PDAs and GPS without mentioningcellular phones, especially as featuresand functionality of the two electronic devicesstart to converge.GPS will play a large role in the future of cellphones.The U.S. government has mandatedthat calls placed by cellphones to 911 emergencyoperators must reveal where the call was made,just like landline telephones. This new programworks by either triangulating a mobile phone’sposition via cellular phone network antennatowers or with a GPS receiver built into the cellphonethat transmits its location.GPS and cellphonesIn 2003, the first GPS-enabled cellular phonesstarted to appear on the U.S. market. Phones likethe Motorola i730, i88, and i58sr cell phones allhave GPS receivers built inside them and arecapable of broadcasting their location. Internetsites and tracking software are available that canprovide you with the location of a GPS-enabledphone that’s subscribed to a location reportingservice.As GPS-enabled phones start to become morecommon, it’s only a matter of time before navigationand map programs start to appear on thephones, which will bring a whole new meaningto using your phone to get directions.Because you’re using the handheld GPS receiver exclusively as a data inputsource — and really don’t care about what’s appearing on its screen — justabout any GPS receiver that can communicate with a computer via a serialport will fit the bill. You don’t need a lot of features and whistles and bells onthe GPS receiver if you’re primarily using it this way. This option makes a lotof sense because the GPS receiver can be used independently of the PDA,especially outdoors during bad weather.The primary disadvantage is that you have to contend with two electronicdevices and the cable that connects them together. This can sometimes get abit messy in a car, with hardware and power and interface cables scatteredall over your dashboard. Also, this type of PDA navigation setup is a bit cumbersometo deal with if you’re walking around.One of the best sources of GPS receiver interface cables for a wide varietyof PDAs is Pc-Mobile. Check out its extensive product Web site at http://pc-mobile.net.Mouse GPS receiversGPS receivers that don’t have a display screen but connect to a computer witha serial or USB cable are often called mouse receivers because of their resemblanceto a computer mouse. A mouse GPS receiver acts as an input devicefor a PDA or laptop and only sends satellite data that it’s currently receiving.