I have the following problem.
When surveying small objects on QField, such as structures with a diameter of 20 to 100 cm (with external GNSS-receiver, +- 1 to 3 cm accuracy), a problem with the preview became apparent.
The preview is not displayed correctly during the measurement and the shape of the preview does not correspond to the object to be measured. But after saving the object and finishing the editing process, it will be displayed correctly on the map.
The same problem reappears in the post-processing of the object, for example when I would like to edit the vertices again (see image below). I suspect that Qfield has maybe problems with displaying the preview in larger scales, because the smaller the scale and the larger the object being edited, the better the preview image.
Unfortunately, this problem makes the measurement of smaller areas more difficult, since during the measurement process, you have no control over whether the measurement is correct or not.
First I thought this might be a problem with the GNSS-signal, but this works fine. And after finishing the edit-process the feature looks correct. The problem also occurs, when the GPS-tool is turned off and a small polygon is drawn by hand (like in the image below). I also tested other polygon-files and formats for example the "simple_form"-layer in the tutorial.
Is anyone aware of this problem or knows how to fix it?
- we try test qfield on archaeological site for the documentation-process
- among other things, even small structures such as pits or post-holes need to be measured (20-100 cm and bigger)
Here some technical information:
- tested with QGIS-Version 3.10 and 3.16 and QField-Version 1.7.6 (on Android-Version 8 Smartphone and Tablet)
- for the measurement in the field we use a Leica Zeno gg04, which works together with an android-tablet, the GPS-signal comes via the "Zeno-connect"- app which is activated in the mock-location