[OSM-talk] Strange location reading

[Oleksiy Muzalyev]

On 27.09.16 21:51, John Eldredge wrote:
> This past weekend, I made a long road trip. At one point, while in a 
> highway rest stop, I checked Google Maps to see how far I had come. To 
> my surprise, it showed me at a different rest stop, about 200 miles 
> from my actual location. I suspect that my phone couldn't get a good 
> GPS reading, and was relying on the WiFi ID from the rest area office. 
> The other rest area was probably using the same SSID.
>
> I didn't think to launch OSMand for comparison, but I suspect it would 
> have given me the same bogus results, as the choice of whether to use 
> WiFi, cell tower, GPS, or a combination, to determine your location is 
> set in the system settings, not inside the mapping applications.
>
GPS signal is not influenced by clouds, rain, and snow. The GPS signal 
frequency of about 1575mhz was chosen expressly because it is a "window" 
in the weather as far as signal propagation is concerned [1]. However a 
coating of water, snow, or ice on a smartphone or on a car may block GPS 
signal. A coating of water, even a fairly thin one is NOT the same as 
raindrops.


So if one is outside and a device is dry, the GPS reading should be 
correct no matter what is the actual weather. Otherwise it makes sense 
to restart the device, or change it if an incorrect GPS location reading 
persists.


[1] http://gpsinformation.net/gpsclouds.htm