Accuracy constraint settings applied to tracking

[rjwillson]

Track Logs are Nicely Implemented on Existing Line Layers but without Accuracy Constraint Setting aberrant vertices get regularly added to track log making it unusable after a few minutes of use (see clip)

Reproduction Steps:

1. start track log on existing line layer

line track log records in background following your every step and allowing user to still add points, lines etc in the foreground

Observed behavior:

track log records but because phone or device will regularly lose lock, aberrant vertices get regularly added to track log making it unusable after a few minutes of use (see clip)

track log in pink, the straight lines are just random vertices being generated when GPS loses lock

happens with internal phone GPS or external bluetooth survey grade GPS connection

Screenshots and GIFs

[Please also attach additional files if a specific project/dataset is useful to investigate the problem.]

**QField version: 1.5.3 Piz Palu

This could be fixed with a track log specific accuracy constraint just like the lines for distance and time, i.e., "don't collect track log vertices unless H RMS (horizontal accuracy) reading is 4 m or less. Development of this accuracy value constraint could also be made as a global option for other layers to add a level of quality control to the data

Additional information:

• Problem started happening recently, didn't happen in an older version of QField: it is a relatively new feature
• Problem can be reliably reproduced, doesn't happen randomly: Yes
• Problem happens with all files and projects, not only some files or projects: Yes

[label-actions[bot]]

This has been accepted as an enhancement request. Good job :+1: Enhancement requests are very valuable to make QField better. They sometimes attract others and just happen magically. More often however they need someone to jump in and make them come true.

[nirvn]

@rjwillson , while not a direct answer to this enhancement request, the following PR should help you: https://github.com/opengisch/QField/pull/4589 -- it allows for users to define a maximum distance threshold between the last and next tracked point beyond which the position is considered erroneous.

[rjwillson]

oh yes, that should have the desired effect on the tracklog, thanks! @nirvn