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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2
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1answer
628 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 ...
1
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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
71 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
votes
1answer
614 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
votes
1answer
153 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 ...
6
votes
2answers
672 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 ...
0
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0answers
31 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 ...
1
vote
1answer
102 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 ...
0
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0answers
30 views

Turning .xy files to .xyz [on hold]

I have a LIDAR dataset which provides .xy data in 2D (hokuyo ust-20lx LIDAR), I want to use gyroscope and GPS to make 3D point cloud in XYZ or LAS format. The most important thing is what application ...
2
votes
2answers
61 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
votes
1answer
29 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 ...
-1
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0answers
13 views

NLCD zonal analysis [closed]

I have been working with the tree cover data for months using both the cathographic and analytic data trying to extrapolate tree cover percent at the census tract level. I first did a raster clip of ...
3
votes
1answer
85 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?
1
vote
2answers
39 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 - ...
4
votes
2answers
82 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 ...
1
vote
0answers
56 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 ...
-3
votes
0answers
24 views

Lidar point cloud 3D segmentation [duplicate]

Is it possible to segment building from the lidar data. Input is only the xyz coordinates. Based on what criteria we can extract the individual building from the point set. Here no image is given as ...
4
votes
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 ...
8
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2answers
2k 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.
2
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1answer
240 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 ...
1
vote
0answers
67 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
178 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 ...
0
votes
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
41 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
261 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
votes
1answer
292 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
77 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
93 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
195 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 ...
2
votes
0answers
57 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
vote
1answer
120 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 ...
2
votes
2answers
191 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 ...
3
votes
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
285 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
votes
1answer
62 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
68 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 ...
15
votes
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 ...
3
votes
5answers
7k views

How to convert LAS to GRID/Raster for ArcGIS input?

I was wondering if there is an option to convert LAS (LIDAR data) to raster or GRID format that ArcGIS could read it.
4
votes
0answers
44 views

How to get NIR values into a LAS file then a CSV?

We are trying to deliver a LAS file with NIR values added for each point. The NIR comes from a raster captured at the same moment as the LiDAR, and is stored as an 8bit number along with RGB in 8bit. ...
4
votes
1answer
287 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 ...
5
votes
2answers
111 views

GRASS r.in.lidar tool generates incomplete rasters

I have been trying to import a huge LIDAR file (10.5) Gb to GRASS GIS using r.in.lidar. It does the task, but only for part of the image, as shown below: Canopy Height Model (CHM) generated with ...
0
votes
3answers
74 views

Extracting impervious areas (buildings, rails, pavements) from LAS dataset [closed]

How to extract impervious areas (like buildings, rails, pavements etc.) from las dataset and receive it like a raster? I tried to do it with intensity, but there are many valids with vegetation. I ...
3
votes
1answer
804 views

wine + LAStools in QGIS 2.8.1, Ubuntu 14.04

I can't get wine + LAStools to work in QGIS 2.8.1 (ubuntu 14.04). I only get the 22 open source functions that comes with QGIS. Outside qgis wine + LAStools works fine. My guess is that I am not ...
1
vote
2answers
74 views

Coordinate transformation in LAStools?

LAStools program only limited to UTM platform for coordinate transformation (las2project, las2transform). Is there any other ways to transform coordinate for local projection in LAStools? For example ...
6
votes
2answers
2k views

Python script using SAGA and arcpy for converting 'on the fly' LAS point cloud to shapefile?

Summary: I have created a process to import a LAS point cloud, clip it, select the ground points and save the output as an XYZ.txt for clients to use. This uses a python based script (will become a ...
4
votes
2answers
212 views

Lightweight python modules to convert LAS data formats to text formats?

I searched on the net and found pyLAS, but it seems to require quite a few other modules and I couldn't get the install right. Any pointers will be much appreciated.
2
votes
2answers
129 views

Using python to batch process lasclip - LAStools/QGIS

I am trying to use the python console to batch quite a few processes from lastools. I'm having trouble with the arguments to lasclip. clipped_las = processing.runalg('lidartools:lasclip', True, ...
2
votes
1answer
51 views

Finding the origin in .laz file with LAStools

I obtained a .laz file, which I used lasinfo and las2txt to view the records. Scale Factor X Y Z: 0.00100000000000 0.00100000000000 0.00100000000000 Offset X Y Z: ...