Methods to obtain high-precision scaling

Hi,

We seek to optimize our surveys of inspection projects requiring high-precision scaling.

Aside from using a theodolite, which are consistent methods for accurate measurements on a building facade or any sort of vertical infrastructure ? The goal is to obtain a centimeter scaling.

Thank you in advance for your answers.

Hi,

It is possible to scale the project by using the Ground Control Point (GCPs) that will improve both relative and absolute accuracy of the project. 

If you are only interested in the relative accuracy, then adding scale constraints would also work. That basically consists of taking real-world measurements and finding those objects in the model and constraining the dimension to match that size. This is typically a good option when you only need to take measurements and are not really concerned with highly accurate geolocation. For scale constraints to be effective it is important to use several in each dimension (XYZ). Also, longer is better, don’t do anything less than a meter in length. More in the How to scale a project article. 

Best,