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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1answer
147 views

Why does my hillshade .ovr display in lower resolution in QGIS?

I have viewed a lidar terrain model hillshade .ovr file on QGIS and Arc and Arc has significantly higher resolution than QGIS. Any thoughts as to why this would happen and ways to enhance resolution ...
3
votes
2answers
63 views

Coordinate formatting for swath data - to polygon

I've got a CSV of Lidar coverage swaths in the below format. Each run or strip is tied together via run_id. I'm assuming L is for left, R is for right and M is for middle. EDIT: These are coordinates ...
2
votes
1answer
184 views

LiDAR data download, merge and mosaic (Minnesota state)

I have been using the toolbox found here to download LiDAR data for MN (Minnesota-US). The tool is very convenient for downloading multiple tiles but the merge/mosaic function of the tool is ...
0
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0answers
372 views

Processing LAS dataset in QGIS 2.8.2 [duplicate]

I need to extract DEM from LIDAR dataset in QGIS 2.8.2. I have installed LAS tools in QGIS. I cannot configure my LAStools because I do not get Processing-->Options and Configuration and instead I get ...
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 ...
2
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0answers
195 views

CPUs to process lidar data using ArcGIS for Desktop?

I am looking to build a computer to process data in ArcGIS 10.2.2. The main use will be to rasterize 10-100's GBs of lidar data. However, I am unclear as to the capabilities of ArcGIS 10.2.2 to ...
3
votes
2answers
117 views

LiDAR GUI tool for selecting and saving groups of points?

I'm working in a small group that is processing LiDAR data with some custom code. We need to see how well our stuff is working so we need samples of "truth" data that we can compare our output ...
2
votes
2answers
294 views

QGIS error when importing .asc LIDAR data

First let me say that I am novice in GIS department. As archaeologist I had only some courses 8 years back when i was still studying. Now, the problem: When I try to import .asc as raster layer I ...
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.
3
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1answer
82 views

Calculate change in canopy height over 10 years?

I want to know how many "tall" trees (greater than 30 m) fell down between 2005 and 2015. I have LIDAR imagery from 2005 and 2015 from an area where many tall trees are known to have fallen due to ...
2
votes
2answers
116 views

Convert from shapefile or raster formats to LAS (preferably free)

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 ...
2
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0answers
588 views

QGIS 2.8 problem accessing GRASS commands

QGIS 2.8.1 Win7 64 bit installed with osgeo4w-setup. I’m trying to run GRASS commands on a LIDAR raster layer but I get the following message: Missing dependency.... GRASS not installed in your ...
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 ...
1
vote
1answer
130 views

How to delete duplicate LiDAR points?

How can I delete duplicate lidar points. I incorrectly read the same las twice and saved as a one file resulting in duplicate XY points. How should I delete these duplicate points?
0
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3answers
107 views

LAS .PTC classes into ESRI LAS to Mulitpoint

We have some Lidar data that has been classified based on visable features (i.e. trees, streets, buildings, etc.) These LAS data are used inside inside Microstation w/ TerraScan connected to a PTC ...
2
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0answers
61 views

Oriented stereopair in ERDAS

I am trying to orient a set of intensity LiDAR images in ERDAS Stereoanalyst for stereo digitizing. The set is consisted of an intensity image and its stereomate. Stereoanalyst is configured for ...
3
votes
1answer
767 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 ...
0
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2answers
846 views

Create DEM with 1 foot contours from lidar data with 1.4 meter resolution

I have Lidar data which contains multiple .las files for an entire quad. I have figured out which .las is the area I am looking for. I was told the data is in 1.4 meter resolution and would work to ...
1
vote
1answer
198 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 ...
2
votes
1answer
584 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 ...
7
votes
1answer
152 views

Extracting wall information using LIDAR data?

I'm trying to extract wall using the LIDAR. I have tried Fusion, Whitebox, Lastools in Arcgis, Saga and Envi. Those are tools that I can use. The walls I am interested are mainly 1 meter high. Some of ...
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0answers
275 views

Format of raw LiDAR data (ToF 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 ...
2
votes
1answer
71 views

Looping for importing and interpolating a lot of LIDAR files?

I'm quite new to Grass Gis and I'm trying to make DEM (digital elevation model) for modelling flooding. I have 170 *.xyz files, which need to be scanned for extents (r.in.xyz -s input=...\filename.xyz ...
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; ...
2
votes
2answers
536 views

Las dataset to raster with ground points only

I'm trying to make a raster from a las dataset. I want to only use points classified as ground, but I can't figure out how to do this. What I've tried is: Create las dataset from 2 .las files. ...
0
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1answer
89 views

LiDAR data for Palawan (Philippines)

Is there any public or private sources of LIDAR data for San Paul river in Palawan (Philippines)? Searching online has not lead me to any sources, and I am unsure how the commercial world of LIDAR ...
4
votes
1answer
272 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 ...
2
votes
2answers
144 views

r.in.xyz doesn't work in GRASS

I have these LIDAR data *.xyz files (1st col x, 2nd col y, 3rd col z) 485000.16 6508997.48 1.84 485001.27 6508998.92 1.86 485001.02 6508996.68 1.85 485000.77 6508994.45 1.79 485000.52 6508992.19 1.79 ...
1
vote
1answer
120 views

LAG LiDAR Analysis GUI installation guide

Does anyone know how do I install LAG lidar Analysis Gui? LAG by arsf This is my situation: I'm using debian 8 test. I installed this library: boost (yes) * GTKmm (yes) * GTKGLextmm (yes) * GThread ...
3
votes
1answer
376 views

DEM creation with C++ application

I am implementing a C++ application that must produce DEMs from LIDAR data. I am following the next workflow: Write .las files from lidar data. Use PCL algorithms to transform/filter the point ...
2
votes
5answers
332 views

LiDAR/Geo-TIFF Tree Crown Segmentation [duplicate]

I am looking for any source code that does tree crown segmentation/delaunitaitoun with LiDAR point clouds or their respective greo-TIFFs. So far I can load and view both LiDAR file and its TIFF in ...
3
votes
1answer
53 views

From LiDAR .txt to QGIS map

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 ...
5
votes
1answer
356 views

Reprojecting LiDAR data with libLAS

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", ...
1
vote
1answer
132 views

Georeferencing las files using liblas

I am trying to write georeferencing information to a '.las' file using liblas and c++. Here is my code: ofstream ofs; ofs.open("test.las", ios::out | ios::binary); liblas::Header header; ...
3
votes
1answer
248 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 ...
9
votes
1answer
581 views

How to georeference LAS files?

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 ...
7
votes
3answers
270 views

Extract DEM and DTM information from LIDAR image using E-Cognition

I´m trying to extract DEM and DTM from a LIDAR file. Currently, I rasterize the image but don´t know which algorithm I need to apply to obtain the DEM and DTM information in different models to be ...
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” ...
4
votes
5answers
1k 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 ...
1
vote
0answers
398 views

LiDAR point cloud to 3D model of street [duplicate]

I am looking for a way to convert point cloud collected through a Riegl LiDAR scanner to a perfect 3D model of a town. The sample data is from vehicle mounted scanner, but final data is going to be ...
2
votes
1answer
731 views

How to create NDVI map From LiDAR intensity and RGB image

I am new with GIS and I've been looking for ways on how I could create a NDVI map from LiDAR intensity and RGB image. Is there any way I could do this? I have read that you could create an intensity ...
4
votes
1answer
262 views

Correct georeferenced LiDAR data

Often I obtain LIDAR data for concept studies and conventional survey (in dxf format) over a small portion of this. The LIDAR typically covers the broader area and is used for broader studies, ...
2
votes
2answers
124 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
2answers
87 views

Selecting percentage of points from multipoint layer (ArcGis)

I am currently working with las dataset of small area, and I want to run some quick analysis on this area. Since my PC is not the best, I am looking for tool like "extract 50% of multipoints to new ...
3
votes
2answers
456 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
3answers
303 views

Which raster resolution (DEM) can I get out of lidar data with variable grid width?

I have ASCII files in *.xyz format and want to generate a DEM out of it. According to the information about the data the *.xyz files are containing variable grid widths - from 1 meter to 4 meter. ...
3
votes
2answers
239 views

LIDAR online training

Beside ESRI's LIDAR online training, I'd like to work on some hands-on training that I can learn about LIDAR. Are there any good LIDAR out there that I can get some training with the datasets ? ...
2
votes
1answer
212 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 ...
4
votes
2answers
2k views

Creating DEM from geoTIFF or asciiGRID LiDAR data?

For a home project I want to 3D print an area from a map. I have downloaded a geoTIFF file and an asciiGRID file from the Tasmanian governments spatial program "TheList". The two files are here: ...
4
votes
1answer
281 views

Convert downloaded LiDAR info to DEM in GRASS

I have downloaded LiDAR information as a .asc file and a .tif file, and even though I have tried multiple methods to convert them to a dem I am having no luck. Grass GIS says there is an invalid ...