I have a layer in my project to record my path when I’m in the field. I use a GeoPackage layer. I set up tracking when I leave my house, then when I’m done in the field or reach home, I stop the tracking. I’ve done this successfully many times in the past. Last night, it appeared to be working fine. I could see the detailed track in the field. After I got home, I stopped the tracking. But when I went to look at the track in QGIS, it was almost entirely gone, with only about 13 points present in close vicinity of my house. Any idea why this happened?
@Craybonn , is the track still fully visible on QField itself? How did you transfer the track to your desktop / QGIS?
The track is also mostly gone in QField as well. I transferred it to my desktop via email via the Files app.
Hey @Craybonn I have heard this from our fieldworkers as well. Since the missing data is noticed after sending the data, it is hard to find the cause. Therefore, I cannot help you with retrieving the data.
Just out of curiosity. Can you tell me for how long you were tracking the position? a few hours or an entire day?
It was tracking for about 6 hours and over about maybe 130 miles.
I don’t know if this is related, but sometimes on my drive home, it will stop tracking during the drive, but get a point or two at my house, so there will be a big jump near the end of the track.
Was your phone on stand-by or were you using another app while driving? QField does not continue recording your position in those cases.
For tracking the phone or tablet should be turned on and QField needs to be open on your screen.
I don’t know what “stand-by” is. But I was using my phone for navigation using the apple maps app. Normally QField does seem to record my position even when I’m navigating with apple maps, but again on the trips home sometimes it doesn’t. QField is open when all of this is happening, just not displayed on the screen.
I was out in the field for the last two days. On the first day, I recorded a track. I could see the track recording fine in the field. Later at the motel, while still seeing a perfectly fine track, I pushed “Stop tracking” and then the track disappeared, apparently completely.
The next day I recorded another track. This time after getting home and pushing “Stop tracking”, it didn’t disappear.
One thing that occurs to me is that the two tracks that disappeared were probably the longest tracks I’ve done. I’ve done probably about 10 other tracks that didn’t experience problems.
@Craybonn , I’m sorry to hear this. It’s something we should absolutely fix here. Once QField 4.3.1 is out, if you could try and find a way to replicate this track loss, I’d be eager to take that information and work through a solution.
When you say longest, what does the track actually record? What are the settings for capturing points? I mean the settings for distance and time in between? Is your track a line geometry?
This is just my wild guess but maybe there is some limitation in number of vertices recorded, or duration of recording? Limitations could be in the QField-software, in the geopackage, in the specific layer, in your phone, something else.
The object is a Line String. Time requirement is on. Minimum time is 15 sec. Distance requirement is on. Minimum distance is 5 m. Sensor data requirement is off. Wait for all active requirements is on. Erroneous distance safeguard is off.
I had chatgpt look at the QField code. It reported that when stopping tracking, the object that holds the temporary copy of the track attempts to store it, then deletes the temporary object without checking if there was an error in the store operation, which apparent is possible. So it might be worthwhile to modify the code so that if there is an error encountered during save, information about the error can be recorded somehow. That information could then be shared with the developers.
@Craybonn That sounds like a big issue. Can you describe this on GitHub? That is the place to report issues like this.
@Mathieu_Pellerin Can investigate this?