vegetation / Tree Removal from DEM

[Mohabon]

As i posted in another topic in GENERAL section, i would like to put this subject also in this section.

With my university we both work with LIDAR datas and Photogrammetric methodologies for MAPPING.

LIDAR is expensive, but it can easily remove vegetation/grass/trees as it uses an emitting source and interferometry criterias to find the "last echo return" that is assumed as the ground, even in very dense scenarios (forests, corn fields, ecc).

As it is said in this topic, the Build Geometry with Height field in PS PRO only gives the top of the envelope, so to manually remove trees / vegation from point cloud or DEM really takes lot of time.
This job is really hard and sometimes it is better to spend more money in LIDAR to save time in processing.

If there were a tool / procedure to find the ("BASE HEIGHT FIELD") = (ground cleaned by trees/vegetation) , we would save lot of money by using photogrammetric UAV instead of LIDAR aircraft.


This is an implementation that could really improved PS Pro market and i am sure many users would pay extra money for having it, my university department included!

Kind regards.

[RalfH]

Given the present price of the PRO version, I don't know if raising the price even higher for each additional feature would be a good idea. Also, I would like to see this feature in the Standard version as well!

[Infinite]

As i posted in another topic in GENERAL section, i would like to put this subject also in this section.

With my university we both work with LIDAR datas and Photogrammetric methodologies for MAPPING.

LIDAR is expensive, but it can easily remove vegetation/grass/trees as it uses an emitting source and interferometry criterias to find the "last echo return" that is assumed as the ground, even in very dense scenarios (forests, corn fields, ecc).

As it is said in this topic, the Build Geometry with Height field in PS PRO only gives the top of the envelope, so to manually remove trees / vegation from point cloud or DEM really takes lot of time.
This job is really hard and sometimes it is better to spend more money in LIDAR to save time in processing.

If there were a tool / procedure to find the ("BASE HEIGHT FIELD") = (ground cleaned by trees/vegetation) , we would save lot of money by using photogrammetric UAV instead of LIDAR aircraft.


This is an implementation that could really improved PS Pro market and i am sure many users would pay extra money for having it, my university department included!

Kind regards.

I would not be adverse to Agisoft LLC upgrading their pricing. Or have another tier or better yet a donation button to help get extra features integrated for developers.

[ajg-cal]

If it helps the problem of blocky fields due to over representation of woodland, I think we'd be happy with an increase in price.

[RalfH]

ajg-cal,

I don't know what you mean by "blocky fields due to over representation of woodland".

[ajg-cal]

Certain features tend to accumulate a huge number of faces at the expense of others, which become coarse and are under-represented. I get this with woodland (lots of faces) and fields (few faces).

[Matt]

Try LASTOOLS its has a several very good pre defined filters for different environments as well as fully manual settings. It can handle billions of points and can be run from command line or gui. For those in a university you get the academic pricing. 

[aespinalp]

Actually you can do that, by classifying points and then creating mesh using just ground points.

After that you can export DTM instead DSM, note that the results may vary depending on how many trees do you have in your project, and also how far are the trees from each other. As more separated are the trees, better results you will get.

This images show DTM and DSM in a GIS software, both generated with Photoscan.

[Darko]

Yes, classifying helps but with the large canopy cover some additional classifying with color would be helpfull too.