Souping Up Your Smartphone's GPS
Even within the search and rescue environment, being off by 15 feet is within acceptable parameters. Search professionals are trained to use their eyes, as well as their navigation gear. This leads to the question: Do we need dedicated GPS devices anymore? Do smartphone advantages of cost, screen resolution and processing power outweigh a classic dedicated device -- even within professional sectors?
Oct 25, 2012 5:00 AM PT
At a recent search-and-rescue boot camp I attended, it was clear during unscientific tests I performed that a standalone, dedicated Global Positioning System device was more accurate navigating to waypoints than a smartphone with GPS chip -- but it was only by a few feet.
A dedicated GPS device that a buddy operated was spot-on when predeployed marker UTM (Universal Transverse Mercator) co-ordinates were plugged in to both devices -- the Android smartphone and GPS -- and both were used to navigate to a flag marker.
The smartphone was off by up to 15 feet. But does it matter?
After a GPS device hardware failure -- a principal button stopped working on my Magellan eXplorist, rendering my classic GPS useless -- I opted to save a few hundred dollars and build out my smartphone as a professional-grade GPS.
Here's how I approached it.
Step 1: Gather the Hardware
You'll need a phone with a true satellite navigating GPS chip. Check the specifications by performing a Web search. The first iPhone, for example, doesn't have GPS.
Assisted GPS, or A-GPS, where the device also uses mobile network signals to supply faster time-to-first-fix, is useful. Alternative GPS system GLONASS is an acceptable 55-satellite addition to the GPS constellation, now showing up on newer phones like the iPhone 5.
Step 2: Switch on Location Services
You can turn on the location functionality within the phone's Settings.
Step 3: Download GPS EssentialsGPS Essentials is available for free from the Android Play Store, or you can get iGPS All in One from iTunes for US$0.99.
Then verify the GPS works by turning on Airplane Mode, rebooting the phone, going outside, and checking for a GPS location fix. The apps you just downloaded will display a location provider and co-ordinates gathered by the phone's location services.
It can take a few minutes. The location provider must read "GPS" not "Network" or "WiFi" or similar, and must show active co-ordinates, rather than blanks or zeros.
Once you've verified your device has a functioning GPS chip that works when mobile networks are switched off, you can proceed to the next step.
Step 4: Download Map Apps
Switch Airplane Mode off, ensure you have a data connection by opening a Web browser and loading a test page, and download relevant map apps from the respective stores. Download $9.99 Gaia GPS (Andoid and iOS) or $9.99 BackCountry Navigator Pro (Android) if your interests are outdoorsy. Both have functions similar to a standalone outdoor-type GPS device like my now demised eXplorist, including high-resolution offline topo maps, tracking and bearings.
Gaia allows for simple export of GPX and KML tracks and import of GPX files. BackCountry Navigator Pro allows for GPX and KML import but has no export function. BackCountry Navigator Pro has better external memory card permutation options, and NOAA RNC charts for mariners. Take your choice -- and you may want both.
For drivers, ALK Technologies' CoPilot Live series of navigation apps range from free upwards, and some include a year's free real-time traffic data. The apps store maps on your device and are comparable to window-mount standalone turn-by-turn in-car, or add-on GPS navigation devices.
Sygic's more expensive app uses the marvelous 3D-rendered cities seen in TomTom sat-nav dedicated devices.
Step 5: Get Your Apps
GPS Assist kick-starts a sticky GPS chip, and GPS Status & Toolbox lets you flush the GPS cache and download A-GPS data for fast fixes. You'll need a network connection for the download itself.
GPS Status & Toolbox provides a fix and satellite status screen too, so you can get an at-a-glance picture of your GPS fix state.
Step 6: Address Power Issues
Extra batteries, or a Lithium Polymer battery pack, plus cable will keep you up for the duration. An in-vehicle cigarette lighter plug is a must for driving.
GPS tracking is exceptionally power-hungry. Use Airplane Mode to turn off superfluous radios like 3G if you're not using them.
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