How Much Can You Rely On the iPhone’s Google Maps Combination of Skyhook Wi-Fi and Cell Tower Data For Pseudo-GPS?
One of the (few) surprises from this month’s MacWorld was that the Google Maps application integrates location data not just from cell tower triangulation (using Google’s “My Location” technology) but also Wi-Fi visibility information, thanks to Skyhook. This combination of technologies piqued my interest, and it turns out that I was in a unique position to see just how these two data sources are integrated into the iPhone’s Google Maps application.
Although Mac Rumors reports that the Skyhook Wi-Fi data trumps the Google cell tower data, the reality is much more complicated, and thankfully more reliable, too! See, I used to live in Massachusetts (where Skyhook has data) and now live in Ohio (where they don’t). So I was able to test the priority of the location data used in the iPhone in a simple way - I compared different good data/bad data scenarios to determine just how Apple is deciding what your location is.
The short answer is, they’ve done a great job programming this and are falling back gracefully when fed bad data. When you tap the location button on an iPhone, you’ll almost always get at least a reasonable location from it, except where Skyhook has bad data and you’ve got no cell service, which is rare enough to be useful.
But if you are using an iPod Touch or iPhone with no cell service, your location data can be woefully incorrect, and even easily spoofed! Although Google Maps location is (probably) not a life and death piece of data, we can be pretty happy with what we’ve been given. But I can think of a whole lotta pranking that could happen once this tech gets more widespread use!
More details after the jump…










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