If you need to proceed with an aerial photogrammetric survey on a construction site with work in progress, you may consider to take advantage of the lunch break to fly with your drone and take pictures.
In “lunch break” workers usually are not around.
And you won’t fly over their head.
And, most important cranes, excavators, trucks, dumpers are still.
Trucks that move around while you’re taking photos could be an issue for aligning images in a structure from motion process.
Where movement is more evident you may have tricky pictures for your software.
It may result in some “holes” or “mistakes” in the sparse point cloud.
In this photo the bulldozer was cleaning a working square in a marble quarry, after an artificial explosion.
It was moving.
The surface was cleaned up and the rocks went away from the top.
The accumulation area below was constantly filled with material that had fallen from above.
Everything kept moving.
I flew my drone (and took pictures to process) in the lunch break, getting all the photos with the “frozen” quarry.
You can use the rest of the day on the field to place the GCPs, measure their coordinates, use your GNSS or the Total Station.
There are a lot of things to do here!
Of course you have to check if lunch break is long enough for your needs and if the light is right for getting “good” pictures.
But if you can, take advantage of this moment.