NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Visual Satellite Navigation
From: Lu Abel
Date: 2016 Jul 11, 16:25 +0000
From: Lu Abel
Date: 2016 Jul 11, 16:25 +0000
Smartphone time accuracy depends a lot on the carrier and your physical location.
I use Verizon and live in the San Francisco Bay area. My iPhone shows the time very accurately.
But I have heard of others living in different areas and/or with different carriers where "phone time" may have a significant lag (at least for celestial purposes).
As I understand it, cell phone towers must have highly synchronized "time" in order to work properly. But their concept of "time" does not need to be absolutely accurate, just relatively accurate within the network.
From: David C <NoReply_DavidC@fer3.com>
To: luabel@ymail.com
Sent: Monday, July 11, 2016 4:18 AM
Subject: [NavList] Re: Visual Satellite Navigation
To follow up your comment about phone time. I have been using my phone as my deck watch and my PC (which is set by NTP) as my chronometer. I had assumed that phone network time would be identical to my PC time but it isn't. The phone is typically 2 - 5 sec slow and can vary over a few hours. For example, early this afternoon I took some sights and the phone was 4 sec slow. I have just checked it and it is now 5 sec slow.I have confirmed that the phone is set to use network provided date and time.I have just restarted my phone and the error is now 0 sec. It seems that the date and time are set only on boot up, not regularly as I had assumed. I suspect that this is a function of my phone's OS (Android) and the time app I am using.Do other phones show this behaviour?
