Best drone for measuring accuracy of steel beams on construction site?

[MNewman]

I was recently asked what drone one should use for the highest accuracy to measure steel beams on a construction sight as it would save a company quite a lot of money from sending a person up there to measure it themselves. I figured I would forward that question here.

The research I have found has unearthed things like LiDAR and Photogrammetry. One website says they're equally accurate. Another says that LiDAR is better. And then ChatGPT says Photogrammetry is better.

That said, are they referring to accuracy when mapping an entire region or accuracy when photographing steel beams up close?
And any recommendations for what drone/drone package would do the trick for accomplishing this task?

 

[Cafguy]

I used to Erect structural steel for a living.
My first question would be: Does your local government not have a building Dept.? in their archives exists a copy of the blueprints used to Erect that steel. If not they DO have the Engineering companies info.
You would need to do more than "measure" the steel, You would need thicknesses as well to be accurate.
You can get sort of a good idea of the sizes by attaching a bright ruler to something and then taking a picture. use the ruler as a measurement guide. It is only semi accurate tho.
For work such as yours and I am assuming Engineering of some kind,.....Sorry, but a good latter or scissor lift and a tape measure is the best most accurate way. There are always archived Blueprints but you must know that during construction a minor change or 2 might have been made and not noted. SO your back to going out there and getting dirty.
If you get yourself a "span" table for structural steel beams it will be a great help to you...Go to your local steel supplier and ask for one.