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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57 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
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1answer
899 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). ...
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0answers
77 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
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1answer
329 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
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1answer
303 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
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2answers
160 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
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0answers
162 views

Converting LIDAR based measurement to UTM coordinate? [closed]

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
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1answer
174 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 ...
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1answer
31 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 ...
6
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3answers
2k 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, ...
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0answers
15 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 ...
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2answers
105 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 name="...
3
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2answers
385 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
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1answer
85 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
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2answers
928 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?
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1answer
64 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
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1answer
44 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 ...
7
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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 (...
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10answers
14k 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 ...
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1answer
100 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
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1answer
221 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
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2answers
226 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, ...
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1answer
110 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 ...
20
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7answers
12k 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....
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12answers
18k 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
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0answers
55 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
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2answers
208 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
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3answers
954 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
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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 ...
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1answer
145 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 ...
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1answer
640 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
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0answers
165 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
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3answers
786 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
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2answers
837 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 ...
1
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1answer
120 views

libLAS georeference las file and update header [duplicate]

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
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1answer
79 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
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1answer
212 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
113 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
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1answer
272 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
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1answer
118 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 ...
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0answers
185 views

Orthogonal correction of building footprints after extracted from a raster

I have ArcGIS 10.1 and am working on a project involving extraction of vegetation and building classes from LIDAR (unclassified) data and aerial imagery (resolution 30x30cm). I have managed to ...
3
votes
2answers
188 views

LiDAR intensity image from multiple flight lines?

I'm working with multiple raw las tiles, and I've used Fusion to create an intensity image, but it shows the flight line overlap (see below). Any idea how can I smooth the image so that the overlap is ...
1
vote
2answers
1k 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.
4
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2answers
886 views

Retrieving average building height in urban areas

I am looking for a way to collect data on the height profile of some cities over time. I don't need to produce a detailed 3D reconstruction of cities, nor do I need to detect and measure individual ...
7
votes
3answers
627 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. ...
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1answer
103 views

Azimuth greater than 360 in Veloview (Velodyne 32)?

When I use Veloview, freezes at 1 of the frames and examine the data points, why are the azimuths greater than 360 degrees?
10
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3answers
1k 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 ...
9
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5answers
1k views

Processing full-waveform LiDAR?

Does anyone know of a good software package for processing full-waveform lidar? Also, does anyone know of a good tutorial on processing full-waveform lidar?
2
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1answer
229 views

Landform design/3D in ArcMap 10.2

Im a self taught ArcMap user working in a small business, so no one to bounce problems off. My aim is this: I would like to be overlay different surfaces, manipulate them, and display them. The ...
5
votes
3answers
805 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) ...