nRF9160 GPS configurations and fixing issues

[Grigor]

Hi.
I’ve developed a custom device based on nRF9160 and now have a problem of fixing GPS signal.
With the same antenna and same conditions sometimes it takes up to 10 minutes to fix, sometimes, 1 minute some times 2 hours and there is no any consistency.
In the datasheet of nRF9160 I found a specification about current consumption of GPS and here there are 3 modes of operation:
•    Continuous tracking, typical peak current without power saving mode
•    Continuous tracking, power saving mode
•    Single shot, one fix every 2 minutes
Could you please inform me which mode is default one? How I can change the operation mode an which mode will provide the best performance for GPS fixing?
In the chapter 8 of the objective product specification of nRF9160 there is an antenna options list. Do I need to configure the antenna type that I’m using in my device and if yes, how to do this?
Thank you.

[Grigor]

Hakon said:

For better GPS performance, you should consider using A-GPS. You can try the nrf_cloud_agps sample project and see if it helps. Also if you haven't done it, you should upgrade the modem firmware to the latest release.

We have just upgraded the modem firmware to the latest one. Actually we tried to use AGPS available in your development branch, but it seems it's not an official release version, right?.   Do you have any estimation when the NCS official release will be?

[Hakon]

Grigor said:

Do you have any estimation when the NCS official release will be?

 

End of Q2 2020.

[xuan0802]

I got the same problem, I run sample GPS alone, I can get a fix in a short time. But when combining with LTE, it can not get fix even a lot of satellites are being tracked. We prototype several circuit using nrf9160, but no circuit is running :(.