[OSM-talk] Strange location reading

[John Eldredge]

This particular rest stop didn't have a cafe, but it did have an office, so 
it seemed likely to me that the office might have a WiFi router for use by 
state employees.

-- 
John F. Eldredge -- john at jfeldredge.com
"Darkness cannot drive out darkness; only light can do that. Hate cannot 
drive out hate; only love can do that." -- Martin Luther King, Jr.



On September 28, 2016 5:21:59 AM Michael Collinson <mike at ayeltd.biz> wrote:

> On 28/09/16 09:59, Warin wrote:
>> On 28-Sep-16 04:44 PM, Oleksiy Muzalyev wrote:
>>> 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.
>>
>> John .. could you have the GPS function on the phone turned off? I
>> usually have mine turned off to save battery power .. for use as a
>> phone. There is a GPS Status app that I use to check various sensors
>> .. including what the GPS is doing, suggest you use it .. that is an
>> android app ... apple should have something similar.
>>
> Do these rest stops have cafes that are part of a chain? They might have
> moved a wifi access point and your app is reporting a non-satellite
> position based on that. I have seen that happen.
>
> Mike
>
>
> _______________________________________________
> talk mailing list
> talk at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/talk