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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2k views

Removing pixel values below 0 in Digital Elevation Model in ArcGIS for Desktop?

I made a DEM layer from a .las file (LiDAR). How can I remove the black area which contains negative values? Is it possible to set these values equal zero or null?
2
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1answer
216 views

Reaching cm (inch) level elevation precision using drones

A road construction firm needs altitude data of road path before and after the construction and the error should be less than 3 cm (2 inch). Normally, they put a ground station and workers manually ...
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5answers
6k views

Easy way to create a boundary polygon shapefile from a set of LAS files using ArcGIS 10?

I have a bunch of LAS file sets that I need to process. The current task at hand is to generate a "footprint" shapefile that contains polygons for each LAS tile. I am looking for a graceful way to ...
3
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1answer
122 views

Converting between coordinate systems for LAS file using LASPY

I am trying to convert a .las file from WGS84 to UTM17. I have some drone imagery that was used to generate a 3d point cloud/ .las file, but it is in latitude/ longitude instead of easting/ northing. ...
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3answers
106 views

Assigning class codes for LAS files? [duplicate]

I have LAS files with code 0 - never classified. I have no other classes other than this. How do I assign class codes for my LAS file?
2
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1answer
248 views

Extracting LiDAR metrics with TerraScan

I want to extract from a las file statistics such as height percentiles (percentile 95, for example) among others. I can do it with Fusion (using Cloudmetrics and Gridmetrics tools), but I would like ...
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0answers
23 views

How to generate DTM from LiDAR point cloud data? [duplicate]

I have LiDAR point cloud data (X Y Z Intensity), and I want to generate DTM (only ground point). Is there any solution (algorithm or software)?
8
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1answer
5k views

Building extraction with LiDAR data (Improve Process)

I have the following process for automatically creating building outlines/footprints from Las files and was wondering if anyone can help improve it or has suggestions for other processes to use? ...
4
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2answers
312 views

Site viewshed with DSM: removing “false” visibility readings from trees and buildings

I've been working on modeling a proposed building and running a visibility analysis to determine from what areas the building could potentially be seen using ArcGIS Desktop with 3D Analyst. Using a ...
3
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1answer
42 views

Differences in the longitude and latitude between a LiDAR DSM and an optical image

I've downloaded the UK's LiDAR elevation data (see below) in laz format for a specific region (Tewkesbury) from: http://environment.data.gov.uk/ds/survey#/download From that, a DSM (Digital Surface ...
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0answers
50 views

Thinning LiDAR points to remove redundant neighbors?

I'm trying to develop a workflow in ArcGIS with 3D Analyst or Spatial Analyst to intelligently thin a grid of spot elevation points created from a LiDAR DEM. The current point spacing is 1 meter. Some ...
3
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2answers
148 views

Converting LAS to DWG/DXF using open-source software?

Is there a way to convert LAS point clouds to DWG and/or DXF files using open source software? Also willing to script with Python - is this possible using libLAS/LASlib for example?
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0answers
157 views

How to generate surfaces of different heights from LIDAR points

I am seeking a way to generate surfaces (polygons in a 3D space) of different heights from LIDAR point clouds, whose spacing is 4 points per square meter. The typical application is like roofs, which ...
7
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4answers
11k views

Viewing .las format LIDAR data 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 ...
3
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3answers
723 views

How to connect contour lines from two different sources?

How to connect contour lines from two different sources (LiDAR & Photogarametry) in order to obtain continuous and uniform contour lines layer ? how can i interpolate them together ? How can i ...
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0answers
340 views

Format of raw LiDAR data (time-of-flight data)

I am doing a project where I need to simulate LIDAR data, and I am looking for specifications on how raw LIDAR data looks. I want the format of the data before it is translated to x,y,z coordinates (...
4
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1answer
83 views

Importing LiDAR .txt in QGIS for map conversion

I have LiDAR data in .txt files (1000 to 26000 KB), where 2nd column marks x-coordinates, 3rd col y and 4th col z. 8 485000.16 6508997.48 1.84 66 Last 2 485001.27 6508998.92 1.86 82 Last 2 485001.02 ...
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1answer
710 views

Visualizing a LiDAR 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 point cloud into QGIS from a datafile. Now I'd like to ...
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2answers
2k views

Tools for exporting coordinates from LAS files to CSV?

Is there any tool available for extracting the X, Y and Z coordinates from a .las file and exporting them to a .csv or similar file?
4
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2answers
123 views

Options for visualizing LiDAR data on (Mac) OS X?

I've recently come across open data LiDAR files for the city of Vancouver. I'd like to view it on my Mac (2011. 10.6.6 OS). My intention is to use the LAS file to identify what the tallest trees are ...
9
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1answer
663 views

Georeferencing LAS files in geographic coordinates (lat/lon) or in cartesian (projected) ones?

First of all, I am a newbie in GIS. I have a lidar point cloud with GPS and telemetry data associated. Then, I transform coordinates of every point to an ECEF coordinate system and finally I ...
3
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1answer
154 views

Identifying flightline ID within an LAS file?

I am working with multi pulse LiDAR data that collects points along a number of lines within the flight path. From what it appears there are four scan lines within the data, at different intervals but ...
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2answers
706 views

Getting the projection of a LAS file using liblas?

I am using the python api of liblas to read/write las files. I would like to get the spatial reference information of the las file using liblas, but have been unable to figure it out. Can anyone ...
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0answers
36 views

Matching drone point cloud data with original lidar survey? [duplicate]

I have point cloud data collected from a drone of a particular area. I too have the point cloud data collected from the lidar survey. Both are georeferenced. Now, I need to match the point cloud data ...
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1answer
111 views

Shifting LiDAR point clouds that have been incorrectly georeferenced

I am new to LiDAR and have never been a part of the LiDAR data pre-processing stage and hence, this question. I have two LiDAR point clouds (.las files) of a densely forested area that were captured ...
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2answers
73 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 ...
2
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1answer
40 views

Assigning CRS using las2las from libLAS?

My las file had a spatial reference of "None." I tried to assign the CRS (in which data were collected) with the following command line: las2las flightline_002.las --a_srs EPSG:32632 lasinfo --no-...
2
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2answers
84 views

Adding LAS files into AutoCAD map 3D with Point Cloud Manager tool

It's my first time to use AutoCAD map 3D for LiDAR. Based on my googling, it is said that I can bring .las file by creating new index and using the Point Cloud Manager tool (the image on the top - ...
5
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2answers
93 views

Improve DTM under forested areas without smoothing?

I'm using a DTM retrieved from LiDAR data and I noticed that forested areas are grainy or not defined. The DTM data was retrieved from geostore.com. Here is one example: Is there any way to ...
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0answers
66 views

Classifying building walls from LiDAR point cloud [closed]

I am currently working on mobile point clouds in order to extract 3D building models in the residential area. I could successfully classify ground, vegetation and building roof lines, but still have ...
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0answers
53 views

Why do first returns have more blanks than last returns in LiDAR data? [closed]

I'm working on an ASCII LiDAR file that has the first and last pulse returns included. Can anyone tell me why a first pulse return may come back with more blank spaces in the data than a last pulse ...
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2answers
3k 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.
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0answers
69 views

Caching LiDAR Image Service outside of ArcGIS to send to ArcGIS Server? [closed]

I have very limited programming/coding experience. We are hosting a number of LiDAR services on ArcGIS Server, and need 24 of these to be cached, from 1:500,000 to 1:4,000. We initially had ...
3
votes
1answer
342 views

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

I went to step 4 from rapidlasso.com 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 interface". Then, step 9 ...
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0answers
25 views

Activating LAStools - 'wrong value for parameter “Msys folder”' [duplicate]

Whenever I try to activate LAStools, I get the following error, despite setting the path as /Users/grant/LAStools/ - which is its actual location: Wrong value for parameter "Msys folder": ...
2
votes
1answer
44 views

Reverse colour-ramped DEM to its original elevation value?

A have a GeoTIFF LIDAR image which display DEM in its color-ramp version (color relief) from blue (minimum value) to red (maximum value) and green (in between). I don't have the original elevation ...
2
votes
2answers
296 views

Running LAStools on QGIS 2.8: “missing dependency. lastools folder is not configured”

To be honest I'm not sure how to run LAStools from within QGIS 2.8. I'm trying to learn by experimentation. QGIS shows all the LAStools in the toolbox If I double click on a LAStool in the toolbox I ...
0
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1answer
301 views

Gridding a LiDAR point cloud? [duplicate]

I have been trying to grid a point cloud, version1.2, LiDAR datasets which are intended to be used for hydraulic simulation of flood propagation. Already, I have used Arc* to work on the traditional (....
3
votes
2answers
88 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
0answers
80 views

LAStools in QGIS 2.8.5: “missing dependency. lastools folder is not configured” [duplicate]

I am using QGIS 2.8.5 Wien and I am trying to install LAStools toolbox. I followed the instructions in rapidlasso.com to install it. I did everything said on the link, but when I tried to run it, it ...
11
votes
8answers
6k 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 ...
5
votes
2answers
102 views

DEM out of a shaded relief LiDAR?

I have a DEM built from LiDAR data and the file extension is .tif. When I open this file in ArcMap it seems to be a shaded relief DEM (see the screenshot below). It happens I want to visualize the ...
1
vote
1answer
235 views

LAStools in QGIS error at activation: “wrong value for parameter 'OTB applications folder'…”

I have a problem with LAStools in QGIS 2.14. I've followed the LAStools instructions for downloading LAStools for QGIS. ` I replaced 'lidar' folder in C:\OSGeo4W64\apps\qgis\python\plugins\processing\...
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0answers
59 views

QGIS 2.12 LAStools lasmerge error: “no outputs specified” [closed]

I am trying to merge 4 .las files with "lasmerge" within "LAStools" in QGIS 2.12 running Windows 7 64. I keep on geting error "no outputs specified" even thoug i did specify the output folder and ...
1
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1answer
127 views

Using lasmerge in QGIS 2.8.3 is not working: “…instance has no attribute”

Every time I try running lasmerge tool from LASTools within QGIS, I get the following error message: Algorithm lasmerge starting... lasmerge instance has no attribute '...
3
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3answers
2k views

Problem using LAStools in QGIS 2.6.1: “global name 'os' is not defined”

I have a problem with LAStools in QGIS 2.6.1. I have never used QGIS to process LiDAR data before. I downloaded LAStools yesterday from the rapidlasso GmbH website. I unzipped the “lastools.zip” ...
9
votes
6answers
308 views

Where can I find open raw LiDAR data for European Countries?

I'm looking for LiDAR data in laz or las format preferably from an FTP site. Does anyone know which countries have that data available to the public? From my research it doesn't seem to be easy to ...
3
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1answer
71 views

GRASS r.in.lidar problem on Windows 10: 'no such file or directory'

I'm having problems to load .las files into Grass GIS 7.0.3 for Windows 10. I use the module r.in.lidar but I get the following message: What can I do? How can I solve the problem?
4
votes
1answer
72 views

30m/10m/1m resolution DEM for microtopography research

I am conducting research in a region of Illinois that does not have a LiDAR dataset. I am looking to develop a fine scale habitat species distribution model; however, the coarse data available (30m/...
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10answers
32k views

Converting XYZ files (with regularly spaced xy) to ESRI GRID format?

Normally consultants (LiDAR survey) provide me with data to my specifications; already in ESRI GRID or ASCII GRID format. This way LiDAR data can be easily used with ArcGIS. This time I only have xyz ...