Using magnetic spheres to do land surveys with a 3D scanner can produce mistakes when you use your land survey software. Here’s a video showing the use of a land survey software to do automatic target-based registration and in this very video, we can clearly see the errors due to false positives (like the head of people) or with spheres that have moved.

Example of 3D scanner land survey mistakes related to spheres that can be moving

In this example, the errors are minor but the narrator clearly says that he has to check to make sure that the land survey doesn’t have significant mistakes like an extra story! Magnetic spheres can be pushed by the wind. This can interfere with land surveying or it will scratch the spheres. Knowing that land survey sphere kits are costly (more than $1K) and often need to be re-painted, it’s a problem that should be addressed.

What if your 3D scanner doesn’t work while land surveying?

Another problem that can happen is if your 3D scanner doesn’t work. What happens if you use regular magnetic spheres (like in the video above) to do your land survey? Well, oftentimes, the professional that surveys the land is different than the professional that reads and analyses the data.

This means that if the data is wrong, the land surveyor has to set up a survey stationing and do the work again which slows down the process.

The advantages of using fixed land survey targets with a 3D scanner

Using fixed land survey targets eliminates the types of mistakes seen in the video above. Moreover, if a scanner doesn’t work, the land surveyor can go back and the landmarks will still be there.

TDR360 offers permanently fixed land survey targets for exterior setups and temporarily fixed survey targets for interior setups like offices. For the latter, everything can be removed a week or two after the job has been completed to make sure that everything is ok.

Knowing that fixed targets are the way to go in land survey and this is why those are the products we manufacture and we promote!