A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2018 Mar 20, 11:21 -0700
Mike Burkes, you wrote:
"I noticed while perusing some sites on smart phones and similar devices latitude and longitude are displayed. How is determined?"
Could you give a little more context? Obviously you know that smartphones almost universally have GPS receivers. When you visit a website, it may ask for permission to use location services. So if you see extremely accurate coordinates, that's where they're coming from. There are a couple of other possibilities. Even without GPS, smartphones and tablets can get your position from a variety of local radio signals. For example, if WiFi is on, the device will check the identities and signal strengths of all available WiFi networks. It will send that data to central servers which will then determine your location with impressive accuracy. Something similar can be done with cell phone towers but it's not as accurate. Next, there's the old-fashioned approach: whenever you visit any website or other service online, your IP address is reported to the site. For most Internet access, this number is tied to an approximate location. It's possible to bypass this with VPN services, and it's also possible to use an Internet access service that shuffles IP addresses, like most mobile phone Internet providers. And finally, there's the case we tend to ignore: you entered your coordinates on an earlier visit and forgot about it. In a case like that, the site simply stored your entered location in a local "cookie" or similar on your computer and it only seems as if the website itself knows your location.
I want a smartphone with a Satelles receiver! Too bad there's no economical path to that right now...