I just downloaded Motion X-GPS last week because that was all I heard about. I don't know if it'll be any good...Any insight?
I haven't used Motion X, so not sure how it will do. One of the key things for me when deciding on a platform for the vehicle was diversity of maps available, web interface for managing maps/tracks/waypoints (gets you off of the little phone screen when you're back at home), active updates/upgrades/bug fixes from the developer, and "cloud" sync. The cloud sync thing is more of a convenience, but it's a big convenience in that is saves you from having to move around a bunch of tracks, waypoints, etc. -- with sync enabled, once you're home and the device with all of your new tracks picks up your wifi, those tracks are backed up to your cloud account and available through the web interface or on your other devices.
Question-
How do these apps track your position if they lose GPS signal? Or is it the map is stored and they still track you via GPS? I don't get it.
Apologies in advance if I'm over explaining here, but figured I'd dump it all out in the interest of information sharing...
<b>How GPS transceiver and map tiles work to plot your location on a picture of a map</b>
The GPS transceiver in your phone/tablet just provides location (just the dot on the map that shows where you are). Maps are normally streamed to the device in near real-time via your mobile data connection. Offline maps are stored local to the device so that when there is no data connection available to download the map tiles, your location (calculated via the GPS transceiver) can still be overlayed on top of the maps you saved to your device.
<b>How the GPS transceiver calculates your location</b>
Your location is calculated by your phone/tablet's GPS transceiver (triangulated by contacting >= 3 satellites -- I'm no expert, but that's the basic on how position identification works). If heavy tree cover causes your GPS to lose signal (e.g., not enough satellites to calculate location) the accuracy of your position will decrease, causing your location indicator (dot) to "drift." I can say anecdotally that the GPS transceiver connectivity in modern mobile devices is generally pretty solid (within +/- 30ft of your actual position) even with tree cover overhead). This will be less of an issue as more leaves continue to fall off of the trees, opening up more sky. As a data point, I still carry my GPSmap62s in the glovebox for emergencies and for fishing/on foot/boat etc.
<b>How a track of your position is recorded</b>
In your mapping software, if track recording is turned on, the map software records the location position data from your GPS transceiver (usually after you've traveled a certain distance (once every 10ft or so)) and displays it on a map as a line showing where you've been.
In other words, the mapping software uses the "temporary" position data from the GPS and saves it as multiple "permanent" location data points somewhere else on your phone/tablet. The mapping software then uses these "permanent" location data points to draw a line and then overlays this line on whichever map you've selected in the mapping software (USGS topo, USFS raster, satellite, etc.). Since the mapping software has saved these location data points as a permanent "track," you can rename the track to something memorable like "Vaseline Vision" for example
<b>How to keep your phone/tablet battery powered up</b>
Needless to say, running screen on full-time plus GPS on full-time is a phone/tablet battery killer. Bringing a power cable (+backup) and adapter for the truck are key for making this setup a reliable primary nav system that you can edit on the fly w/ custom maps.
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That's way more than I set out to write, but hope it helps... gonna go get some work done.
