Number of GPS satellie used to obtain a location

[flau]

Hello Everyone,

I am currently using the AGPS example on the nRF9160-DK with nRF Connect SDK v1.7.0.  I notice it requires 4 satellites in order to provide a position fix.  Initially I thought 3 satellites are all that are required to obtain a GPS location.  Am I wrong?  Is there a way I can speed up the position fix process if I only need the longitude and latitude for my application?  Can I do it with just 3 satellites?  

Thank you very much.

[Charlie]

Hi Flau,

I think the discussion about Why does GPS positioning require four satellites is out of the scope of nRF9160. You can find the theory behind it from other more professional communities on GPS.

Getting only longitude and latitude does not affect the speed to get a position fix. It is the process to search and choose satellites effect Time to first fix. The current solution is AGPS. You can find a comparison of different types of location services from this table. It is basically a trade-off between speed and accuracy.

Best regards,

Charlie