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.

learn more… | top users | synonyms

2
votes
1answer
146 views

Extracting desired LiDAR points with Quick Terrain Modeler

There may not be a 'better' or 'easier' way to do what I'm asking, but I figured I'd give it a shot and ask around. I'm using Quick Terrain Modeler v8.0.3.4 (x64) and have used the ZEB1 Handheld ...
2
votes
1answer
161 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
71 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 ...
3
votes
3answers
415 views

Removing duplicates from large LAS files

Are there any publicly and free (not necessarily open-source) applications that can remove duplicate points from LiDAR clouds? I would like something on the lines of lasduplicate -unique_xyz, which ...
1
vote
0answers
175 views

How to increase FUSION-LTK lidar processing productivity?

I am processing Lidar data with FUSION-LTK. My study area contains 5 blocks of 1000 las tiles per block. Each block is broken into approximately 4 subblocks of 250 las tiles. I am calculating grid ...
2
votes
0answers
219 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 ...
2
votes
1answer
203 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 failing....
2
votes
2answers
1k views

Installing LASTools to QGIS on a Mac (or other LAS processing plugins)

I recently saw this link how to install LAStools toolbox to QGIS. The problem is that the instructions are only for Windows users. Now I wonder if it's possible to install LAStools on a Mac with QGIS ...
2
votes
2answers
331 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 ...
1
vote
0answers
159 views

LiDAR dataset displaying 500 meters to the east of correct position

Why does my LIDAR dataset show up ~500 meters to the east of the correct position even though a spatial reference/coordinate system is provided? Some background: The LIDAR data were downloaded from ...
6
votes
1answer
185 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. ...
2
votes
1answer
74 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 ...
2
votes
0answers
596 views

QGIS 2.8 problem accessing GRASS commands [duplicate]

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 ...
5
votes
2answers
391 views

Creating planes, eg roof surfaces, from LiDAR/DSM data

I am capturing the area of roof tops of buildings from a DSM (derived from LiDAR data) which has not been much of a problem. I can then also derive angle, hillshade and aspect but it is only per-pixel....
3
votes
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
3answers
212 views

What can I do with lidar returns of 6 or greater in LAS 1.2 specification?

I have lidar LAS data that contains a number of points that represent returns 6 or 7. The data is supposed to be in ASPRS LAS 1.2 specification, which does not allow return numbers (echos) greater ...
1
vote
1answer
123 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 (...
1
vote
1answer
141 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?
2
votes
0answers
64 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
260 views

Correcting class codes of LiDAR files in ArcGIS

Is there any procedure to automatically correct lidar classification? My LAS Dataset has water listed as ground and buildings listed as vegetation. Just wondering if there is any option to fix this.
2
votes
1answer
96 views

Make a ground mask raster with the Greater Than tool

I'm trying to see if I can replicate the Esri solar suitability site example from this article. I fail on the creation of the binary ground raster. I have made a Bare Earth raster from LiDAR ground ...
7
votes
1answer
597 views

Looking for free / open source Lidar web viewer?

I have lidar data which I want deploy my users using web viewer. I will probably hold the data in PostGIS (not sure yet). Is there good open source/free lidar viewer that I can integrate with ...
2
votes
5answers
374 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 ...
0
votes
1answer
95 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 ...
2
votes
2answers
163 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 ...
3
votes
1answer
408 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 cloud....
4
votes
1answer
294 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, ...
3
votes
3answers
2k views

Creating DSM and DTM from a LAS using a freeware solution

Is it possible to export a surface and terrain model files from an aerial, LiDAR point cloud (LAS) set? I am using SAGA GIS for very basic operations, but I couldn't find this option (and I have a ...
2
votes
0answers
401 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
815 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 ...
3
votes
1answer
236 views

Lidar and Opengeo suite

Opengeo suite has provided a tutorial on how to manage LiDAR data using postgresql. I was trying to follow the tutorial in this link. I am new to Linux and using Ubuntu 12.04. I have successfully ...
4
votes
1answer
301 views

What are definitions of watershed segmentation, local maxima, variable window search, regarding LiDAR for vegetation?

I am not familiar about Lidar. I want to measure trees height and number of trees. I guess, watershed = to locate the trees, local maxima = to measure trees height. I used these methods in SAGA GIS. ...
2
votes
2answers
89 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 ...
1
vote
1answer
293 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 ...
4
votes
3answers
331 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
278 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 ? ...
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
294 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 ...
2
votes
2answers
2k views

How to create DEM from Lidar point cloud data? [duplicate]

I'm using ArcMap and I want to create DEM(s) over an area to have different outputs depending on which settings/filters I put in. I have access to laser point cloud data as my input files. I've worked ...
3
votes
2answers
72 views

Using ASCII LiDAR data tiles which are centimeter rounded (n Z) in ArcGIS Desktop seems to round them to meters?

I try to use four LIDAR tiles in .asc with arcgis9.3. All of this tiles are centimeter round (in z) but one of them seems to be round to meter (see tile on the left up corner on the image below), ...
2
votes
1answer
221 views

How to convert different lidar data formats to raster DTM and measure its geographic position accuracy?

I'm trying to generate a DTM from lidar data and I'm new in the this field. I have different kind of files which describe the same area (different versions): *.dtm *.xyz *.xyz with variable grid ...
2
votes
0answers
142 views

Mine Grid to UTM

I have been given spatial data (lidar) that was collected in mine grid feet in ASCII format. I am using arc to process but need to define a projection does anyone know how to do this or any other ...
3
votes
1answer
227 views

What's the deal with “degradation” and lastools?

I've read a few cautions online and heard a few from colleagues. If you don't purchase a license for lastools, the non-open-source functions will somehow degrade your data or results? Is this true? ...
2
votes
1answer
558 views

Load LAS files in MapInfo

Is it possible to open LAS files within MapInfo? If so, how is accomplished in MapInfo 10.0?
2
votes
1answer
347 views

Analyse slope gradient from LiDAR .asc data

I'm new to using QGIS. I have purchased some LiDAR data which downloads as .asc format, is there a way to analyse the terrain slope angle from this data or does it need to be converted into DEM? ...
2
votes
3answers
723 views

Merging multiple rasters with the SAME spatial extent

So I began with lidar elevation data 1m resolution, and I performed a terrain analysis to extract specific ranges of elevation from the raster (1st picture is 0-1m elevation, 2nd picture is 1-2m ...
3
votes
2answers
572 views

Removing incorrect (non-ground) points from LiDAR data? [duplicate]

I have ground lidar points, nonground lidar points and tree lidar points. The problem is some of the ground lidar points are incorrect. For example, the highest elevation values of tree and building ...
5
votes
2answers
259 views

How to filter LiDAR data by scan angle?

I am looking to filter LiDAR data (.las format) by scan angle specifications (e.g. keep all points < 15). From a basic Google search, it appears that the LibLAS library has the ability to filter by ...
4
votes
2answers
301 views

Problem with Y offset shift of LAS file (las2las)

I'm trying to set the origin of a georeferenced .las point cloud to be coordinates 0,0,0, essentially stripping the georeferencing. The only way I could think to do this was subtract the minimum X, Y ...
11
votes
2answers
3k views

Huge point cloud laser data in PostGIS - Storing and Processing it

I wonder, how it's possible to store huge sets of laser scanned point cloud data in PostGIS, with the time-aspect for processing it in mind. I know, there exists a geometry-object Point in PostGIS. ...