On the Edge with the iPhone, Scoping GPS and 3G Coverage
This is the Warner Trail in Moose Hill Audubon Wildlife Sanctuary, what is essentially my front yard. That’s my wife up ahead, Gyasi the Ridgeback likes to lag behind us. We take this trail most weekend mornings, so long as it’s not pouring, in the winter, spring, summer and fall. We often see Deer, Coyote, Turkey, and the occasional Fisher Cat on the trek. That’s one in the picture on the right. They’re like a weasel on steroids, about 15-20 lbs. of gnarly teeth and claws! Very nasty animal!
It took about 5 minutes before the iPhone GPS was able to obtain a position, but once it did, it tracked us fairly accurately. I should mention that Sharon MA, particularly this part in Moose Hill, has one of the highest elevations on the east coast up to 30 miles inland. That’s aside from Blue Hills in Milton MA, which is at 635 feet above sea level. We’re approximately 530 feet above sea level, so I don’t know if that helps the GPS or not. There’s a fire tower not far from here in Moose Hill that spies most of southeastern Massachusetts, from which on a clear day you can actually see the tip of Cape Cod.
Click the image to enlarge

The highway in the upper left is US Route 95, about equidistant between Boston MA and Providence RI. The road to the right of the blue GPS beacon is Rt 27, which cuts through Sharon center. And the detail just above the blue beacon is a cleared swatch of woods for power lines.
I got 3-4 bars of Edge signal here. When we were a little further south, at the start of the trail, I had 3-4 bars of 3G signal, only about 3/4 of a mile away. I’m not sure why there would be such a delineation. Could it be because of the power lines?