GPS for Dummies.pdf - Engineering Surveyor

110Part II: All About GPSMouse GPS receivers are about half the size of the smallest handheld GPSreceivers (Figure 6-1 shows the size differences between several GPS receivers),but even so still have good satellite reception with open skies. Another advantageto a mouse GPS receiver is you can place it in an optimal spot on yourcar’s dashboard for satellite reception and then mount the PDA in the mostvisible place for driving. Depending on the model and type, a mouse GPSreceiver can be powered by a cigarette lighter adapter, rechargeable batteries,or the device it’s plugged in to.Although mouse GPS receivers are smaller than handheld GPS receivers, youstill face the cable clutter issue, plus you can’t use the mouse receiver to getsatellite data unless it’s connected to a PDA or laptop.Some of the vendors of mouse GPS receivers (and their Web sites where youcan get product information) include DeLorme: www.delorme.com Haicom: www.haicom.com.tw Holux: www.holux.com Mapopolis: www.mapopolis.comGPS receiver cardsSome GPS receivers take the form of a card that you can plug into a PDAexpansion slot. The two types of GPS receiver cards are Memory cards: Most PDAs have a memory card slot that supports aCompact Flash (CF) or Secure Digital (SD) type of memory card. Both ofthese card formats also support hardware devices that can be embeddedinto the card: in this case, a GPS receiver. (PDAs without internalmemory card slots might have optional expansion packs that plug intothe PDA and provide a memory card slot.) PC Cards: A PC Card (also called a PCMCIA card) is a hardware expansioncard designed for laptops. PC Card devices include hard drives, modems,and GPS receivers. These receiver cards are mostly used with laptops,but some PDAs support expansion packs for using PC Card devices.Using a GPS receiver card with your PDA means that you don’t need to worryabout an external GPS receiver or cables. You just plug the card into a slot, andthe GPS receiver starts accessing satellite data. However, note these drawbacks: Slot competition: CF and SD memory cards that function as GPS receiverstake up the expansion slot that’s used for additional PDA memory. Battery hogs: GPS receiver cards quickly run down your PDA’s battery ifyou’re not connected to an external power source.