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Maybe the algorithm used an average processor time and there's a lot of variation ("jitter") in latency?
This could potentially put Bill's cell phone farther away. A variation of only +/- 1 microsecond means +/- 0.186 miles of error. +/- 10 microseconds means +/- 1.86 miles.
This may be a moot point if the ping happened when the phone was inside a moving vehicle.
OtherHand wrote:My guess is that it's debris from local hikers of some years ago. The area northwesterly of there, Nola Cove (?) used to be a private inholding in the park with a number of cabins. All appear to be now gone with some foundations still visible on aerials. Still, you picked about as remote a spot to poke around in as possible. My hat's off to you there. BTW, the plateau-like area at the southwest corner of your map is a wonderfully scenic spot that's little visited. Pretty easy to get to from lower Covington, once the annoying climb is out of the way.
Part of the answer came from Mike Melson, cell phone guru. Recently Mike shared with me some cell phone testing he had performed in the lower Covington Flat area. It’s an area about 10 miles from the Serin Drive cell tower with marginal to non-existent cell signal coverage. Mike was using an Android phone with an app that told him when he was connected to the Serin Drive tower (just another damn thing I can’t do with my iPhone!) What he did was send text messages while noting his precise lat/long position and the time. Later, he was able to obtain from Verizon the distances from the tower Verizon’s system recorded for his transmissions. The bottom line was that the distances Verizon recorded were very close to the actual positions, usually less than a few tenths of a mile off. Most of the time the errors were on the near side with the system thinking he was ever so slightly closer to the tower. This was probably due to reflections off higher rock faces increasing the path length. But overall, Verizon’s path length measurements were very close, strongly suggesting their 10.6 mile measurement for Bill’s ping was in fact accurate. Validation of Verizon’s system also implies that any true distance for Bill beyond, say 11.1 miles (within 10% of 10.6 miles to quote the Verizon tech) would be a physical impossibility. This excludes all areas southerly of Smith Water Canyon, such as Quail Mountain and Lang Canyon. You know, those areas we spent so much time on.
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