[GPS] is inaccurate / [Location] red spot sparkling by around location not exactly where we are.

[regina_kim]

Description : red spot sparkling by around location not exactly where we are.

step+current result :

1. open location
2. searching location where i am.
3. red spot shining when fixed location --> but location is not correct

expected result :
it should be shining correct place where i am.

[jeremy]

This should be the issue of hardware or firmware of ublox chip, This issue needs to go to contact with vendor. Nmea log will be attached later.

[will]

Thanks to some insight from Marek:

GPS is known to be inaccurate for several reasons which are
explained in detail on the web. I collected a few links that should serve as
a starting point:

Easy to understand summary:
​http://en.wikipedia.org/wiki/Dilution_of_precision_(GPS)

A rather scientific page with lots of examples:
​http://www.earthmeasurement.ca/GPS_accuracy.html

Another summary:
​http://www.sailtrain.co.uk/gps/limitations.htm

[jeremy]

Hi, as I observed, the gps chip seems to get a fix as possible as based on the signals it received. I tried to hold at the same position under good environment to get a fix, it started with a non-precise but close fix then quickly drift to precise position. Then I walked toward to and along building edges with not really good environment, it happened to lost the fix and got a worse non-precise fix soon again, back and forth. The logs are attached.
It indeed is affected based on degrees of Surrounding conditions, but that's chip's behavior. We may ask vendor and compare with other products to distinguish it's an issue or not.

[jeremy]

drift nmea log grepped

[john_lee]

i don't think there is anything we can do. even if we can find a better chip, gta02 is already shipped.