LIDAR (Light Detection and Ranging or Laser Imaging, Detection and Ranging) is an active optical remote sensing technology that measures properties of scattered light to find range and/or other information of a distant target.

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4
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1answer
482 views

Failing to merge rasters in QGIS

I am new to QGIS but have some familiarity with other GIS software (namely ArcGIS). I want to merge a number of LiDAR digital elevation model (DEM) tiles (specifically, 30 individual tiles) to ...
2
votes
0answers
348 views

Extract road defects from terrestrial LiDAR, in Erdas 2012 or ArcGIS10.1

I'd like to extract road defects from a lidar point cloud. So, wherever a road surface drops or raises by a few mm relative to 100 cm around it. I know it's possible but I just can't find or figure ...
4
votes
1answer
2k views

arcpy “The table name is invalid”

I wrote a script that, ideally, loads raw .las (LiDAR data) files into a geodatabase, then creates a terrain from the multipoint files that are created. When I run the script though I get: ...
2
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0answers
40 views

Reference file paths stored as attributes in Model Builder

I'm trying to design a model in Model Builder that will derive input files for a process from file paths stored in an index shapefile's attribute field. The two datasets involved are a shapefile ...
2
votes
1answer
64 views

Creating a Terrain from a Multipoint file if the “New Terrain Wizard” is missing?

I created a multipoint file using the tool LAS to Multipoint in ArcMap. After it was done processing, I went to my geodatabase, right-clicked and attempted to create a terrain. However, the wizard ...
1
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0answers
33 views

Creating a reference line among LiDAR points and retrieving distances between them?

I have a LAS dataset which contains points with x and y coordinates. For further analysis I need a new dimension which can be adjusted as the dataset requires. To make it understandable I made this ...
2
votes
1answer
60 views

Merging more than 9 input files with lasmerge?

Is there a possibility to feed more than 9 LAS files to lasmerge tool? The user interface only allows 9 LAS files from LAStools toolboxes in QGIS or ArcGIS, but at liblas.org it’s described as there ...
1
vote
1answer
53 views

ArcScene can't symbolize LAS points by classification code or number of return

I'm using ArcScene 10.3 and loaded a LAS file into a LAS Dataset. When I look at the LAS files statistics I can see that there are several classification codes and 7 different returns. Everything ...
2
votes
1answer
746 views

Converting LAS file to .asc DSM? [duplicate]

I want to count trees in SAGA GIS and I am trying to follow the steps described in Counting trees using segmentation and vectorization in SAGA Gis from dominoc925.blogspot.com (05th, March, 2012). ...
1
vote
0answers
69 views

Reduce Z value precision in QGIS

The .asc LiDAR files provided by the environment agency have height values provided to a precision of the level used to measure atoms. How to quickly lose a few of the pointless digits on the end to ...
2
votes
1answer
291 views

Reading las files with laspy [closed]

New to laspy and encountering an error. The first code block describes the file header, the second (In[24]) fails to open the file with laspy: In [21]: import numpy import laspy from laspy.file ...
3
votes
1answer
258 views

How complete are the Fusion tools in QGIS?

How complete are the Fusion tools in QGIS? I have them installed and (vaguely) working, but there are only about ten of them. Is the idea of having just a few tools available, that one can use ...
5
votes
2answers
141 views

Can LiDAR differentiate between rock and soil?

Can LIDAR by itself, tell the difference between rock (large and small) and soil? I'm under the assumption that the answer is no. However, I wanted to check here with the experts as I was told by ...
3
votes
0answers
142 views

Converting LIDAR based measurement to UTM coordinate?

I have lidar based measurement with azimuth elevation and range, I would like to convert this data to UTM coordinate. I know the position of the lidar in UTM coordinate system, so I developed the ...
2
votes
1answer
167 views

Filtering noise out from bare-earth DEM with terrace fields?

I have a 1m bare-earth DEM, derived from LiDAR data, representing a terraced landscape. For the sake of any subsequent use of the DEM (e.g., least-cost path, cost surface analysis, and the like) I am ...
0
votes
1answer
29 views

Fixing Pixelation in DSM [duplicate]

I ran las dataset, then las to raster using max for DSM. Two and a half hours later I have 3 areas showing pixilation using higher level coloring. See enclosed image. I found on web that seamless ...
5
votes
3answers
1k views

Determining bare earth from unclassified LAS file?

I have data in LAS format with RGB values created from Aerial photogrammetry using a UAV. I am trying to find a solution to extract the bare earth to create my DTM from the DSM. I have tried SAGA, ...
0
votes
0answers
13 views

How to classify a LAS file into ground points and vegetation [duplicate]

I have a dense LiDAR point cloud in .LAS format for a forest. All the points are unclassified. Just wondering how to manually classify the points into ground points and vegetation. I noticed that a ...
1
vote
2answers
68 views

PDAL: Couldn't create filter stage of type 'filters.voxelgrid'

I have the following PDAL pipeline: <?xml version="1.0" encoding="UTF-8" standalone="no"?> <Pipeline version="1.0"> <Writer type="writers.pgpointcloud"> <Option ...
3
votes
2answers
206 views

Creating DEM from las file without using Lastools

I want to create a ground model from a *.las file. The LAStools are available in QGIS but limited in use (generation of black diagonal in result file), so I can't use this. In the GRASS tools I can ...
2
votes
1answer
70 views

Creating multiple LAS datasets from LiDAR files in various directories using model builder?

I have 60 folders each containing approximately 20 LiDAR files in .las format. I want to create one LAS dataset from .las files from each folder, and each LAS dataset is named by the folder name. I ...
3
votes
2answers
858 views

Canopy Height Model of LiDAR data in QGIS?

I am having a DTM and DSM files. I want to develop a Canopy Height Model in QGIS. Is it possible?
-2
votes
1answer
59 views

Expression into the raster calculator to invert DEM

I've made a DEM from first pass LiDAR data which I want to invert and run watershed segmentation and basin delineation over in order to hopefully extract tree canopy outlines and heights - I'm newish ...
1
vote
1answer
37 views

Leica Cyclone 5.1 TLS Data referencing using Trimble DGPS

I am using a Leica HDS3000 Terrestrial Laser Scanner (TLS) and Cyclone version 5.1 to acquire and process point clouds. Within the manual for Cyclone 5.1, Leica mentions that a user can enter the ...
3
votes
1answer
249 views

Classification of above ground LiDAR points in ArcMap

I recently used the LAS Dataset toolbar to classify a .lasd file. The process classified the majority of points as unassigned with the rest being ground points. The study area has many tall buildings ...
7
votes
4answers
1k views

Assigning RGB values from Geotiff image to LiDAR data, using R

I have given a Geotiff image and its corresponding Lidar data (x,y,z) in UTM coordinates. I need to merge the Lidar data with the RGB values from the image. That means, at the end, I need to plot ...
10
votes
10answers
12k views

Where can I get pointcloud data? [closed]

Is there any freely available pointcloud data? I'm especially interested in dense clouds of small areas(5m to 100m radius) but anything else would be fine too. Edit: I've found that these pages ...
0
votes
1answer
84 views

How to find the height information from LiDAR point cloud data [duplicate]

I need to find the biophysical parameters(biomass) from the LiDAR point cloud data. For that I need the height of the trees from the data. Currently I am having the general height with respect to sea ...
5
votes
1answer
153 views

Merging .asc files = “The command line is too long”

Having problems merging LiDAR .asc folder files to produce a single GeoTiff file. I have followed various instructions e.g. the 2 methods of selecting input files for merging .asc files using ...
2
votes
2answers
199 views

Laz LiDAR files display extremely long thin line of points

I am having difficulty properly visualizing aerial LIDAR data from the csc.noaa.gov source. Taking any of the .laz files, the point cloud displays as an extremely long thin line of points. Zoomed in, ...
0
votes
1answer
84 views

Reset a base elevation in Pix4D?

Does anyone know how to set a baseline elevation in Pix4D, or is that something that has to happen on the drone-capturing side? The reason is that I have an area which is flown with LiDAR, several ...
19
votes
7answers
11k views

Methodology for creating accurate drainage networks (and catchments) from high resolution LiDAR DEM?

This is not the first time I've stumbled over this issue; it seems that I am unable to generate a correct drainage network model and the resulting catchments from full resolution (1m cells) LiDAR ...
7
votes
3answers
10k views

Viewing .las format LIDAR data in QGIS?

Is there an easy path to visualizing this LIDAR data? I have QGIS, and some USGS LIDAR data in (.las) format downloaded from http://lidar.cr.usgs.gov/ . This means I have both the (.las) and ...
25
votes
12answers
17k views

Working with LiDAR data using other than Esri software?

I will be working with LiDAR data soon and I am wondering what the alternatives to using Esri software to do this are, including open source solutions?
3
votes
0answers
54 views

LasDatasetToRaster does nothing to the Raster Layer

I have been trying to figure out how to clip and rasterize a LiDAR map file programmatically (Not through arcpy) I use C# but read many languages. So far I have been able to access and assign the LASD ...
7
votes
2answers
178 views

Are PDAL or PCL capable of producing LiDAR grid metrics?

I typically use Windows-based FUSION to generate grid metrics, which can be used to describe forest structural characteristics. From the FUSION documentation: GridMetrics computes a series of ...
9
votes
3answers
636 views

Costs and requisites when hiring aerial LiDAR survey [closed]

My organization is considering hiring a company to capture new LiDAR data to help with current stormwater issues that we are currently experiencing. I am a GIS analyst that has been assigned with this ...
0
votes
0answers
21 views

UK Environment Agency Lidar data [duplicate]

I have recently downloaded LIDAR data from the Environment Agency website in the form of asc file. In order to perform some viewshed analysis do I have to convert these files into a raster file and ...
1
vote
1answer
91 views

Open a SBET file format in GIS software

After a LiDAR flight, we can get a file containing the airplane trajectory in SBET format - Smoothed Best Estimate of Trajectory. Is it possible to open it in a GIS software like QGIS or ArcGIS? If ...
1
vote
1answer
610 views

Reading SBET file in python?

I have an SBET (Smoothed Best Estimate of Trajectory) file that I would like to read in python. I found these links that discuss options for reading/writing SBET files, but I was wondering if our ...
2
votes
0answers
138 views

Problem reprojecting LiDAR data using liblas

I have multiple lidar data sets and I am trying to reproject them using liblas. They are missing the coordinate system in the header information so I assign them an SRS using las2las --a_srs: las2las ...
7
votes
3answers
646 views

Filtering out canopies and buildings from DSM to have a bare earth elevation

Can anyone suggest methods in filtering out trees and buildings from a DSM so as to come up with a reliable DEM? What I have is a grid from a LIDAR data (.tif file, with 1m resolution). I was going ...
6
votes
2answers
770 views

How to de-noise a DSM

I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
2
votes
1answer
587 views

How to visualize a point cloud in 3D with GRASS?

I'm new with qgis and grass so I'm sorry if there is a straightforward answer for this question but I can't seem to get it done. I've imported a pointcloud into qgis from a datafile. Now i'd like to ...
1
vote
1answer
91 views

libLAS georeference las file and update header

I am just starting to use libLAS and I had a small issue. I have next code to generate a las file with georeferenced points: std::ofstream ofs; liblas::Header header; liblas::SpatialReference srs; ...
3
votes
1answer
68 views

How exactly does a single laser pulse from LiDAR act? [duplicate]

I'm trying to understand the behavior of a single laser pulse in a traditional airborne lidar. I understand that the multiple return values are representative of the surface that reflected the ...
1
vote
1answer
134 views

Creating building footprints from LAS files

I wish to create building footprints from the classification in our LAS files. I have filtered out the building points, using the point cloud filter. But I now trying to join the outermost points of ...
3
votes
1answer
95 views

How to exclude water during contour generation?

I recently acquired a LiDAR data set that included a 1 meter DEM. I generated 1, 2 and 5m contour layers but I am seeing a lot of contours within water bodies. I suspect this is either caused by wave ...
1
vote
1answer
200 views

Calculating coverage of vector polygon over other polygons?

I have a shapefile file that contains a LiDAR footprint and I'm trying to figure out how much a county is covered by the LiDAR footprint. Two separate shapefiles. The attribute table for the county ...
4
votes
1answer
111 views

Obtaining sink morphometry from local minima points

I am working on LiDAR data from GIS and R and I want to extract landforms from the DEM. I have found a method to obtain local minima points of my LiDAR data. However, I would like to obtain the ...