Since I’ve been playing around with my Garmin eTrex Vista HCx for almost a year now, I realized I’ve never tested out the GPS capabilities of my iPhone that I got only a few months after the eTrex. I always assumed that the iPhone wasn’t as accurate as the dedicated high-sensitivity GPS receiver. So what do you think? Is the iPhone’s GPS receiver less accurate than a handheld GPS?
When I hiked up Ascutney a few weeks ago, I turned the iPhone GPS tracker on near the top of the mountain to test it against the eTrex that I was already carrying in my pack. Here’s the result:
View iPhone GPS test in a larger map
Not bad, I think. The red line is the eTrex, and the blue is the iPhone, running Gaia GPS Lite. As far as accuracy, they seem pretty similar. The only major difference seems to be how often each was collecting a data point. I had manually set the eTrex to collect a point every 30 seconds (the recommended setting takes a point every 100 or 200 feet of travel, but I prefer the timed collection), and I think the iPhone must have been collecting points based on distance. The iPhone seems a tiny bit more jittery with its data points, but if you’re not zoomed in super close it seems accurate enough.
So why carry the eTrex? On day hikes I might stick with the iPhone only, but I’ve used the eTrex for three 8-hour days in a row on one pair of rechargeable NiMH batteries (I haven’t tested the non-rechargeable lithiums yet). The iPhone ate through most of its battery power in four hours or so. For longer trips, if I want to have a track of where I’ve been, the eTrex has a much better battery life as well as batteries that can be replaced in the field. That’s the major advantage for simply tracking my progress.
That’s all for now. I thought some people might like to see the comparison.