GPS for Dummies.pdf - Engineering Surveyor

Chapter 6: Using GPS with a PDA107 Ruggedness: Handheld GPS receivers are designed to take more abusethan PDAs, which often fail when they’re dropped or knocked around.Although you can buy ruggedized (with special enclosures that makethem waterproof, drop-proof, bear-proof, and kid-proof) PDAs, they’reconsiderably more expensive than off-the-shelf models; expect to spendat least several hundred dollars more. Weather/water resistance: Unlike GPS receivers, PDAs aren’t designedto be waterproof or even weatherproof. This can be a major issue if youplan on using your PDA navigation system outdoors in damp, rainy, orsnowy weather, you’re around water, or you have a leaky water bottle inyour backpack. Power considerations: Most PDAs use internal batteries that arerecharged through a docking cradle. If you’re away from a power source,this can be a serious issue because you can’t swap out dead or dyingbatteries for a convenient set of spare AA or AAA batteries like you canwith a handheld GPS receiver.When it comes to weighing the pros and cons of PDA navigation systems, youreally have to examine your needs and planned use. If you plan on using aGPS receiver exclusively for road navigation, you should definitely consider aPDA. However if you’re going to be using GPS primarily in an outdoor setting,you’re probably better off with a handheld GPS receiver.Although PDAs are relatively fragile and don’tget along well with water, you can find productson the market to protect them when exposed toharsh environments. Among my favorites areOtterBox cases. For a well-spent $20–25 for thelower-end models, these plastic containersdefend a PDA or other electronic devices fromMother Nature as well as not-too-carefulowners.OtterBox has two products that let you operate aPDA (including using its stylus) while encased ina waterproof and crushproof housing. One model,the Armor 3600 shown in the figure here, has awaterproof portal that allows you to connect thePDA to an external GPS receiver with a serialcable. There are also accessories that accommodatethe oversize external antennas of GPSOtterBoxesreceiver cards and sleeves. Tests performed bythe U.S. Forest Service indicated no satellitesignal degradation when GPS receivers wereused in the Armor cases.The Armor series of cases do add bulk to the sizeof your PDA. However, considering the protectionthat they offer, the rugged cases are well suitedfor anyone who wants to venture out into thewilds and use a PDA without worrying about itbreaking. A 3600 Armor model will set you backabout $100; OtterBox also has other Armor casesfrom $20–50.I like to think of the OtterBox Armor products asaccessories that turn your meek and mild PDAinto a tough and rugged Humvee. To find out moreabout the products, check out www.otterbox.com.