@<movq https://www.uninformativ.de/twtxt.txt> "(#7bhzgaq) @lyse Depends, sometimes it’s within specs (you can expect something like 3 to 15m accuracy 68% of the time, IIUC), sometimes it’s 200m off (like in my test this morning) and doesn’t get better even if you wait and don’t move. But I admit that was an extreme case that I’ve only seen a couple of times. Obviously I won’t share my real GPS tracks here. 😅 So I made a couple sketches. On a good day, it would look something like this: Green being a GPS track made with a good tracker. It’s already wobbly, even if you’re walking in straight lines, but it mostly matches your actual path. Red is the bad phone. Maybe I could have lived with this if it had been a cheap phone (which it wasn’t). In fact, my previous phone was *way* cheaper but had much better results, comparable to the green line, so this was quite a bit unexpected and disappointing. On a bad day, it would look more like this: Basically useless. And most of the time, it would take several minutes to get a “fix” in the first place. Meaning I was standing in front of my house for 5-10 minutes, waiting. The better phones get a fix within 5-30 seconds. (I suspect that somehow A-GNSS was broken or partially broken on the bad phone, but no idea, really. The GPS hardware is a blackbox.)"

Fri, 27 Oct 2023 18:51 Z (8 months ago)

@lyse@lyse.isobeef.org Depends, sometimes it’s within specs (you can expect something like 3 to 15m accuracy 68% of the time, IIUC), sometimes it’s 200m off (like in my test this morning) and doesn’t get better even if you wait and don’t move. But I admit that was an extreme case that I’ve only seen a couple of times.

Obviously I won’t share my real GPS tracks here. 😅 So I made a couple sketches. On a good day, it would look something like this:

https://movq.de/v/f95a556bed/sketch0.png

Green being a GPS track made with a good tracker. It’s already wobbly, even if you’re walking in straight lines, but it mostly matches your actual path. Red is the bad phone. Maybe I could have lived with this if it had been a cheap phone (which it wasn’t). In fact, my previous phone was way cheaper but had much better results, comparable to the green line, so this was quite a bit unexpected and disappointing.

On a bad day, it would look more like this:

https://movq.de/v/f95a556bed/sketch1.png

Basically useless.

And most of the time, it would take several minutes to get a “fix” in the first place. Meaning I was standing in front of my house for 5-10 minutes, waiting. The better phones get a fix within 5-30 seconds.

(I suspect that somehow A-GNSS was broken or partially broken on the bad phone, but no idea, really. The GPS hardware is a blackbox.)

#b35s7za