DTM for Mapping

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

Hello, Admin

 

I want to known the how to remove Noise data Such as. tree, building and forest area for producing DTM.

Myint Naing

MD

GAI

myanmar

2

Hey Myint, 

Try to add manual tie points where there is a noise. It should improve the quality of your DTM.

1 Like
3

Hi Myint, 

Trees, buildings and dense vegetation areas can be removed from the point cloud with the automatic point cloud classification or with the point cloud editing tool. These two articles describe these procedures in more detail:  
How to automatically generate a Digital Terrain Model (DTM)
How to edit the point cloud in the rayCloud

There is also a video about how to generate the DTM: https://www.youtube.com/watch?v=NjCiTHTKXr8

If the question was related to removing noise in the reconstruction, then adding Manual Tie Points (MTPs) as Selim recommended should help!

4

Hello Admin,

I am using the Phantom 4 RGB camera in order to map some forest plots.  My goal is to produce the ortho- mosaic of the plots and also a DSM of the plots. Regarding to the DSM, I would like to get the trees height  in order to compare it to a validation information from the field. I  notice that the DSM that i produced included the mean sea level, meaning that when I checked the height of a certain tree, this height was included the mean sea level. Is  it possible to get the DSM of only the tree without the mean sea level? is it possible to get it in two different products? 

 

Thanks, Best regards,

Moshe

5

Hi Moshe,

 

I believe you could extract the heights from the trees by subtracting the DTM from DSM in a third party software as QGIS.

 

I hope this helps,

Ina