A high resoution orthomosaic helps you can clearly identify all the stone elements of an ancient road’s pavement.
It’s really useful if it’s required to remove the stones and, at the end of the work, put them back in their original position.
You can use a camera mounted on a pole and aimed to the ground or a drone flying over and shooting nadiral photos (the camera is pointing downwards).
If you are allowed to fly, a drone could provide an easier image acquisition process.
Photogrammetry softwares with SfM (structure from motion) algorithms process them and generate an orthorectified, georeferenced and high resolution image: the orthomosaic.
You can upload it in a CAD or GIS softaware, below under the project plan.
And it is measurable!
A project team can integrate the drawing with the information taken from the pictures and make very detailed executive output.
The level of details of the orthomosaic depends on the GSD (the Ground Sampling Distance).
The higher the details needed, the lower the GSD should be.
This means that you have to take closer pictures, lowering the distance between the drone and the ground.
If the area is large you may have a lot of photos to process (and archive) but it is still much more comfortable than using a terrestrial camera.