Questions tagged [lidar]

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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10
votes
4answers
7k views

Determining bare earth DEM 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 DEM from the point cloud. I have tried SAGA, ...
8
votes
3answers
4k views

Normalizing point cloud data

How I can get Digital Height Model (only object heights, DSM - DTM = DHM)? Many applications can do this, but they convert it to GRID or TIN format. I was wondering if it was possible to keep the ...
7
votes
5answers
15k views

Converting LiDAR data to raster (DEM/DSM) for ArcGIS input?

I was wondering if there is an option to convert LiDAR data (.las) to a raster/grid (DEM/DSM) format that ArcGIS 10.0 can read?
10
votes
5answers
12k views

Clipping LAS data using shapefile polygons and open source software?

I am trying to clip or filter lidar files (.las, .xyz) using a shapefile that contains multiple polygons. Is there open source software that can do this spatial operation? My .las files are enormous,...
7
votes
2answers
2k 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 ...
16
votes
7answers
35k views

Viewing LIDAR data (.las) in QGIS?

Is there an easy path to visualizing LIDAR data in QGIS? I have some USGS LIDAR data in .las format downloaded from http://lidar.cr.usgs.gov/. This means I have both the .las and metadata in .xml ...
10
votes
4answers
4k 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 (...
6
votes
4answers
10k 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 ...
7
votes
3answers
3k views

LiDAR (.las) to bare-earth DEM: average points spacing and cell size?

I am using ArcGIS 10.1 to generate a DEM (bare earth) from LAS dataset. To accomplish this, I use Las Dataset to Raster tool as described in Esri website. I have read here and there in the web that ...
12
votes
5answers
5k views

Extracting tree crown areas from remote sensing data (visual images and LiDAR)

I am looking for a method to process a remote sensing image and extract the crown areas of the individual trees from the image. I have both visual wavelength areal imagery, and lidar data from the ...
12
votes
4answers
5k views

Comparing two Digital Elevation Models (DEMs) from LAS files?

I have two LiDAR files (.las), one is original let's say with X points. And the other is copy of the first .las file but with Y points, where Y is less than X. Now, I want to compare the Digital ...
14
votes
6answers
2k views

Ways to visualize multiple large LiDAR tiles?

I want to load approximately 10 large LiDAR tiles for analysis. I have tried using ArcScene but it appears there is a limit on how much data ArcScene can handle at one time. Each tile is 65-90MB in ...
8
votes
4answers
3k views

Thinning large LiDAR point cloud?

I have a large point cloud (LAS file) and I am trying to thin this using a complex technique. I know it is possible to thin a point cloud using simple techniques such as extracting every nth point. ...
25
votes
12answers
27k 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?
28
votes
7answers
18k 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 data....
11
votes
7answers
11k views

QGIS 2.14.1 LAStools install error: “wrong value for parameter 'Msys folder'…”

I went to step 4 from How to install LAStools toolbox in QGIS guide and extracted LAStools to my C drive and just made the folder there. I can't do step 8 because it seems to already be in "advanced ...
9
votes
3answers
5k views

Workflow for determining stream gradient?

As far as data goes, I'm working with NHD .shp files, 10m DEMs, and some LIDAR data. My goal is to determine gradient for 100m segments of a network of streams. I'm already able to do this, but I ...
6
votes
1answer
2k views

Reprojecting LiDAR data with libLAS, error: “latitude or longitude exceeded limits”?

I have a lidar file (file.las) with the following spatial reference: Spatial Reference: PROJCS["NAD83 / UTM zone 11N", GEOGCS["NAD83", DATUM["North_American_Datum_1983", ...
4
votes
1answer
256 views

Selecting LiDAR return point type in LiDAR dataset with ArcPy?

I am trying to create a Digital Earth Model (DEM) using ArcPy under ArcGIS Pro 2, but I am running into some problems. I can generate a DEM within ArcGIS Pro by selecting only the ground points ...
20
votes
9answers
15k views

Viewing LiDAR data from web browser?

I am looking to host lidar data on my own server and give clients the ability to view that data through a web browser as a 3D point cloud (file would be in .las format or equivalent), possibly with ...
12
votes
2answers
13k views

What are LiDAR returns?

Can someone help with an explanation and some references, in order to understand the nature of return pulses within a LiDAR system.
5
votes
2answers
891 views

Retrieving LiDAR metrics from relative vertical layers of point cloud?

I need to obtain the proportion of all returns within 5 equally spaced height bins between the cutoff (1 meter) and the maximum height value. I need to get this proportion of all returns for 1000 ...
6
votes
3answers
2k views

Finding outliers with wrong Z values in LIDAR data

I have more than 2000 XYZ (only ground points) .txt files and I have to do Quality Control (QC). Let's say I have file, which I converted to multipoint (or even singlepart feature). I have mean Z ...
2
votes
3answers
4k views

Converting a .lasd (Lidar) coordinate system?

How can one change a coordinate system for a .lasd (Lidar) dataset? The file is currently in UTM_Zone_15N and I am trying to convert it to IL_East.
6
votes
3answers
2k views

LiDAR data density, returns per square meter

How can I compute a raster showing the number of return points per square meter using SAGA GIS or other open source software? My goal is to obtain a mask which would show me the places (cells) ...
1
vote
1answer
602 views

What is the definition of pt_spacing on Point File Information tool?

I can't find any definition for the outputs of Point File Information tool (3D analyst), specifically the pt_spacing field. Is this the average distance between points, or the average number of ...
14
votes
16answers
25k views

Seeking point cloud (LiDAR) 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. I've found that these pages have ...
5
votes
1answer
757 views

Making a 3D map with shapefiles, lidar and aerial image data

I want to try to make a simple 3D map for a small area (10 square miles) with some housing, some roads and some vegetation on it. My geodata is as follows: shapes with houses/roads/vegetation. ...
10
votes
3answers
27k views

Converting LiDAR files from LAZ to LAS format

I'm trying to convert LiDAR files from the LAZ format (the compressed version) into LAS (the uncompressed version) using LASzip software. However, I am not really sure how it works. I created a new ...
4
votes
1answer
879 views

Deleting anomalous points in *.lasd using ArcGIS for Desktop?

I am using ArcGIS 10.3.1 for Desktop. I have a raw .las file that I have brought into an ArcGIS .lasd file format. The raw data has several anomalous points; i.e. the maximum elevation for any point ...
4
votes
2answers
4k views

Clipping from a tiled LAS dataset with LASTools (for ArcGIS)

I have huge amounts of lidar data stored as tiled datasets per project. The "tiles" are separate LAS files based on our national map sheet setup (800 by 600 meter). To keep an overview of the data I ...
4
votes
2answers
961 views

Classifying raw LAS data as bare earth in ArcGIS for Desktop?

I have a raw LAS data that has only one return (no second/ third.. return) and not classified yet. The only information I have is intensity and elevation. Is there any way that I can classify bare ...
2
votes
1answer
718 views

Clipping LAS data with multiple shapefiles

I am looking for a method to clip with multiple shapefiles (139 shapefiles polygon) a lidar.las file. I'm using the software Fusion, as described in: How to clip LAS data using shapefile polygons ...
2
votes
2answers
326 views

Pixelated DSM using LAS Dataset to Raster?

I am using ArcGIS 10.2.2, and I am trying to create a DSM out of some LIDAR data. After checking the LAS Dataset properties, I see that I have an average point spacing of approx 0.3. I tried ...
1
vote
1answer
195 views

Tracking which LiDAR data tiles have been delivered?

My company works with LiDAR data for large electrical transmissions systems (thousands of miles in one project). We model the transmission lines and do analysis using CAD and GIS workflows. We break ...
22
votes
6answers
17k views

What LiDAR processing tools are available in Python?

I have been using FUSION and the command line FUSION Lidar Toolkit (LTK) to process LiDAR data. A broad Google search ("Lidar Python") yielded libLAS and pyLAS as Python LiDAR libraries, however, ...
18
votes
3answers
2k views

Account for bridge overpasses in a ground DEM to allow for water flow under the overpass

I have a bare earth DEM made from lidar data (A). It works well and has passed all accuracy tests. It is used in storm surge models. The problem we are having is on underpasses. I need to allow water ...
10
votes
8answers
4k views

Editing LiDAR point cloud to remove noise/outliers present below and above ground?

I have "dirty" LiDAR data containing first and last returns and also inevitably errors under and over the surface level. (screenshot) I have SAGA, QGIS, ESRI and FME at hand, but no real method. What ...
4
votes
1answer
3k views

Installing LAStools in QGIS 2.4?

Does anyone know where the Processing menu moved in QGIS 2.4? Specifically, I am trying to install the LAStools box for QGIS following these instructions: http://rapidlasso.com/2013/09/29/how-to-...
13
votes
3answers
5k views

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

From time to time, we use LiDAR data for modelling in ArcGIS. Previously, we would be supplied either an .xyz or .ascii of the data, but more recently, we are also being provided .las files in ...
7
votes
3answers
6k views

Classifying LiDAR data with LAStools?

I am presently using LAStools to analyse LiDAR data. Can LAStools classify the points into various features such as vegetation, roads, buildings etc? If so, how is it done?
6
votes
1answer
2k views

Converting LAS 1.4 to 1.2

LIDAR files were released for major part of Slovenia few months back in zlas format. Decompressed LAS format is 1.4 version. I have tried many options how to generate DEMs and had some success in ...
1
vote
1answer
115 views

Batch processing LiDAR files (.las to raster) with PyQGIS?

for layers in glob.glob("*.las"): processing.runalg("grass7:r.in.lidar", "input_las",5,1,"",1,100,"","",5,"","",False,True,True,"331289.57265,337990.42735,4558790.0,4560890.0",0,layers+"E:/...
5
votes
2answers
1k views

Comparing two TINs created using ArcGIS for Desktop?

I have the following two files: LiDAR las file1 Let's give it a name LiDAR las file2, contains the same file1 data, where number of points randomly removed. So if file1 contains X number of points, ...
3
votes
1answer
945 views

Classifying 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 ...
3
votes
3answers
1k views

Removing las2dem streaks from raster DEM?

I've created a series of DEM files using the las2dem tool from LAStools; however since I don't have a licensed version they have black streaks running across them. Does anyone know a good method for ...
3
votes
2answers
2k views

Converting from shapefile or raster formats to LAS? [closed]

I am looking for a solution to convert either from ESRI shapefile format to LAS or from a common raster format to LAS. I have access to following software: ArcGIS 10.2 for Desktop (arcinfo with ...
3
votes
1answer
726 views

Specifying LAS dataset filters in ArcGIS ModelBuilder?

I'm trying to create a tool in the ArcMap ModelBuilder to extract a canopy height raster from LiDAR data. I need to create rasters for ground elevation and first return. I've got my LAS dataset, and ...
2
votes
1answer
641 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
117 views

Which QGIS installation for Windows comes with r.in.lidar?

I am running QGIS 2.18.14 (QGIS code revision: ff83b9a479) on a windows 7 machine, it comes with GRASS 7.2.2 (Code Revision r71496), but it does not come with r.in.lidar. I have noticed QGIS 2.18.16.1 ...