Elevation Data not accurate?


#1

I am new to DD and want to know how I can get accurate elevation numbers. I did a flight for a piece of property that we are building a new building on. Right now it is only site work and one other existing building on the property. The map turned out great, although I flew at 80’ and now everything I am reading says fly higher. When I check elevation of the existing building it calculates about 11" lower than it is and the new building pad is calculated lower as well. Any suggestions on how to get this closer?

Also, is there anything out there that will give me elevations in relation to sea level not just AGL?

This is a very interesting app and I can see several possibilities for using this in my business.

Thanks!


#2

Are you using ground control? That is the biggest single thing to getting much better elevation data and a more accurate map in general. If not, read up on the DD support articles regarding ground control.

Hope this helps,

Steve


#3

The default (non GCP) elevation will be relative to the drones takeoff point being 0 (within ± 20 feet based on the GPS accuracy in the drone and GPS sky conditions that day. To get the height of the building, you would have to check the height of the ground next to it and subtract that from the height of the building indicated.

You would need to use GCP’s on a business account to get elevations set to sea level.


#4

I will read up on ground control. This is day three with the software, so I know there is a lot to learn. I am currently using the trial version, so I am assuming I have to upgrade and then buy the GCP, if I read correctly? If I purchase the GCP, then does that eliminate the use of a survey marker? Sorry for these questions, just new to this but eager to learn. Thanks!


#5

It depends on what you need from an elevation standpoint. If you need real-world values you need GCP’s. If you just want to know heights and calculate volumes of standalone objects I would suggest using the oblique after mission feature. It will greatly improve vertical structures. Or use the orbit feature that can be found in many other apps.