All Questions
149
questions
0
votes
0
answers
50
views
Combine DTM with hillshade in QGIS
I'm wondering if it is possible to combine a LiDAR generated DTM on a 1m Scale with a Hillshade DTM on a 0,25m Scale to improve the level of detail of the LiDAR DTM.
If possible how can this be done ...
1
vote
0
answers
33
views
How to augment LiDAR/DSM data from 3d models
For a viewshed analysis in QGIS 3.34, the I have LiDAR/DSM geotif files available. I want to modify/augment the DMS layer by adding the height information from 3d models of specific buildings. This ...
0
votes
0
answers
147
views
DEM from LiDAR using cloud compare
I am working on overseeing a comprehensive flood analysis project in Bardonecchia, Turin, Italy, post the August 2023 flood event.
I have been handed over the LiDAR file .las in which flood occurs.
I ...
0
votes
1
answer
49
views
Plotting real (normalized) las values on dtm
I am trying to plot a las where I filtered objects, that have a first and a last return simultaneously (objects in the las file), onto a created dtm of the same las. I am able to produce a good result....
- 3
0
votes
0
answers
99
views
How to derive first return points from a raw LAS data file
I have a raw (never classified) las dataset derived from UAV that I am attempting to obtain a DEM, DSM, and eventually CHM from. I have successfully been able to classify ground points and vegetation ...
- 1
0
votes
0
answers
38
views
How to have a good rendering with mdenoise - DTM LiDAR denoising
I'm trying to generate a clean slope map from a LiDAR DTM. Due to LiDAR high resolution, the slope map is full of noise.
So to do this, I use mdenoise library.
It works quite well but it generates ...
- 83
1
vote
1
answer
608
views
LiDAR LAS to DEM in QGIS 3.22 without LAStools
I'm using Ubuntu Linux and have installed QGIS 3.22 which has native support for LAS files. I think that LAStools is for MS Windows only?
I can load the LAS data and see a pretty image.
Next, I want ...
- 121
2
votes
0
answers
125
views
Plotting Mean High Water Mark from DEM LiDAR around mangrove vegetation
I am currently trying to plot a Mean High Water Mark (MHWM) using a 1m DEM created from LiDAR. I have been able to plot a contour value representing MWHM based on tide gauge data. When I create the ...
- 21
0
votes
0
answers
67
views
DEM derived from LiDAR in wrong location
I am trying to derive slope and aspect from a DEM that was derived over a mine using LiDAR in ArcMap v 10.8.1 . However, the DEM seems to be in the wrong location (further North from the Area of ...
- 67
0
votes
1
answer
218
views
Float32 to UInt16 terracing problem [closed]
I have the same initial problem as the links below, but I cannot change to using float32 as I am not using Blender.
Terracing / stepping artefacts after converting lidar DTM from float32 to uint16
...
- 43
0
votes
1
answer
150
views
Accuracy of LIDAR from XYZ and DEM comparison
I'm taking point cloud xyz's from LIDAR and turning them into DEMs, then comparing that DEM, to a DEM of the original 3D CAD Models to see how well the LIDAR is measuring the model for elevation and ...
- 1
0
votes
0
answers
102
views
Processing a LiDAR image to be more detailed
I'm using ArcMap 10.8 to try and find old roadbeds. The DEM data I downloaded is very dark and shaded. You can't see anything at lower elevations. I have the hillshade effect turned on but you can't ...
- 1
0
votes
1
answer
509
views
LAS2DEM QGIS No Results
When I try use LAS2DEM in QGIS, the results are an empty file:
I have followed all setup instructions with the LAStools zip folder (in a C:\ with no spaces or special characters in the path, and set ...
- 1
3
votes
0
answers
39
views
LiDAR derived streams - map scale
Historically, streams were defined by the map scale. For example, for a map with a scale of 1:24,000 would mean that the streams identified on that map would be 1:24,000 streams.
With streams that are ...
- 31
1
vote
3
answers
431
views
Terracing / stepping artefacts after converting lidar DTM from float32 to uint16
I am a beginner QGIS user, using it to supplement other skill sets in 3D modelling and rendering.
I am trying to use UK lidar data in Blender to render 3D topographic maps. For this to work correctly ...
- 29