A few questions regarding GPS

[jeanpierrraubry]

regarding GPS i made the following test on 3 phones together
i ran these tests a few tens times each
all of them in GPS only mode

XA2 Ultra with SfOS 5.0.0.68, GPSInfo + OSM Scout
time to first fix: very erratic, from almost immediate to more than one hour
battery drainage: usually very high average over 10%/hour

another strange fact
very often when i take a train GPS will locate me at the Paris station 300 km away

FairPhone 2 with SfOS 3.0.0.8, GPSInfo + OSM Scout
time to first fix: usually almost immediate
battery drainage: usually less than 1%/hour

Huawei MYA-L11 with Android 6 SatStat + OSMAnd~
time to first fix: usually a few minutes
battery drainage: usually much less than 1%/hour

what is wrong?

[nephros]

@jeanpierrraubry

XA2 Ultra

It has been discussed quite a few times in this forum that the XA/XA2 series are problematic wrt. GPS reception.

[rodolphe.sequeira]

Regarding GPS on Jolla C2 with SfOS 5.0.0.68, GPSInfo + Magic Earth:

time to view >=3 satellites: usually almost immediate

time to first fix: usually a few minutes
battery drainage: usually very high average over 10%/hour

Also Magic Earth positioning is often very unstable while driving, even when 7 GPS satellites are in use (that should provide good accuracy of around 4 meters): how is it possible ?

[jojomen]

@jeanpierrraubry

XA2 Ultra with SfOS 5.0.0.68, GPSInfo + OSM Scout
time to first fix: very erratic, from almost immediate to more than one hour

Time to first fix on my XA2 (non-Ultra) is also often quite fast, but sometimes takes 20 minutes or so.

@jeanpierrraubry

very often when i take a train GPS will locate me at the Paris station 300 km away

Are you using the Mozilla location packages? Maybe that station is where SNCF say the IP address you got from the onboard WiFi. Anecdotally, I have observed worse GPS performance when using the Mozilla packages - it seems that when I get a coarse fix quickly I can wait “forever” for it to improve.

[jojomen]

@rodolphe.sequeira

Also Magic Earth positioning is often very unstable while driving, even when 7 GPS satellites are in use (that should provide good accuracy of around 4 meters): how is it possible ?

At least some of us have lots of trouble with GPS on the C2, see this thread:

How to make the GPS work with a Jolla C2 (Sailifish 5.0.0)?

Turns out it takes forever again after rebooting the phone or restarting GPS apps. The cellular or WiFi positioning seems to be broken, and finding satellites takes a long time too. Once connected to a satellite, it lost the connection multiple times and jumped around on the map. So, it is very unreliable. This is how the GPS worked on the Jolla C2: [Screenshot_20250509_110623_Komoot] And here the same route using S24U: [Screenshot_20250509_110700_Komoot] I put this in my feedback post. Fe…

Symptoms include generally “noisy” GPS position and sudden jumps, that can be hundreds of meters. I have even seen position jump maybe 400 m followed by smooth tracking that was parallel to my path and off by 400 meters!

[jeanpierrraubry]

@jojomen

Are you using the Mozilla location packages?

not as far i know, i never installed it, but maybe it got installed by some app?
how do i know if it is installed and used ?
my settings are GPS Only

@nephros

It has been discussed quite a few times in this forum that the XA/XA2 series are problematic wrt. GPS reception.

i know that and have read these threads which did not help very much

i have a dream:
somebody from jolla gives a statement about that!!!