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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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 ...
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1answer
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What Lidar processing tools are available in Python?

I have been using FUSION and the command line FUSION Lidar Toolkit (LTK) to process Lidar data. A broad Google search ("Lidar Python") yielded libLAS and pyLAS as Python lidar libraries, however, ...
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109 views

How to handle multiple space separator in Grass?

I try to load a Lidar point cloud in .xyz format to Grass (in QGIS 2.0.1). I tried to input the following options to the 'separator' field: tab, 'tab', '\t'. Just for the unlikely case that it ...
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3answers
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How to clip LAS data using shapefile polygons and open source software?

I am trying to clip or filter lidar files (las, xyz) using a shapefile that contains multiple polygons. Is there open source software that can do this spatial operation? My las files are enormous, ...
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1answer
147 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 ...
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76 views

Finding obstructions along a stream with LIDAR

I'm trying to find obstructions to boat traffic (downed trees, collapsed bridges, etc) along medium sized streams (5-15m across). The obstructions may or may not obstruct water flow. I have good ...
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1answer
169 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? ...
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1answer
108 views

What tools or opensource library could I use to deal with LIDAR data(mobile laser scan data)? [duplicate]

I would like to do some reasearch job relating to automatic objects extraction along the road, like road markings, pole-like objects. I have to pre-process the original data before applying my own ...
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119 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. ...
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1answer
129 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
153 views

Work flow for Lidar and OCAD

I am updating our maps for an orienteering club in Ilinois. I was very excited to find out that we have access to .las lidar data in 2000x2000ft files. I checked out OCAD11 and it can handle .las ...
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1answer
115 views

Clip raster with shapefile

I want to clipping raster (Lidar) with shapefile in qgis ver.2.0.1. Which plugin in qgis could I use it ? Thanks for help me.
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2answers
320 views

How do I get the projection of an 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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1answer
356 views

How do I read 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 ...
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1answer
254 views

Where to obtain LiDAR Data for Romania?

I need LIDAR Data for realizing a urban hydrology study (Romania areas), whence I can get this data? There is a chance to obtain data for this area (Cluj-Napoca city)? I'm PhD student are chances to ...
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2answers
3k views

Proper workflow for LAS to DEM conversion

I regularly come across LiDAR (.LAS) files with elevation data. When I do, I always struggle to find a way of converting them to a DEM for hydrological analysis. I have developed several workflows, ...
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1answer
877 views

How to create contours from smoothed DEM instead of using Terrain to Raster?

I'm fairly new to working with lidar and have been assigned the task of creating 2ft contours for the entire county using USGS-provided lidar tiles. Is there a significant difference in the accuracy ...
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2answers
454 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 ...
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1answer
108 views

How to determine line numbers within an LAS file?

I am working with mulipulse 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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1answer
157 views

How to add points to LAS copy using liblas?

I am trying to make a copy of a LAS file while inserting new points using python liblas module. The code below creates the copy and adds the points, but for some reason the added points are not in ...
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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 ...
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104 views

How can I convert LIDAR based measurement to UTM coordinate?

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 ...
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1answer
151 views

How do I use a DHM in tiff format for distance and slope measurements?

I am a student and I have to work out a project about soil loss on a plot. I need basic measurements of this plot such as length, width, area and slope for my erosion calculations. I have got my ...
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37 views

LiDAR Basics - How classes are determined at LiDAR data? [duplicate]

LiDAR data have classes as Medium vegetation, Buildings, Ground, Model Key and more. What determines these classes ? is it combination of intensity and scan angle rank ? how to reclassify these ...
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1answer
146 views

How to add LiDAR Intensity attribute to a point feature class?

I need to convert LASD (ESRI LAS Dataset) to ASCII text file. I've export the data to point feature class (LAS to Multipoint), converted multipart to single part and calculate X Y and Z.My first ...
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2answers
324 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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3answers
583 views

How to convert LAS file to numpy array?

I have begun learning how to manipulate LAS data in python and wanted to see how others handle LAS files. I would like to read the points (I am using a numpy array), and filter out classes 1 and 2 ...
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1answer
318 views

Load LAS files in MapInfo

Is it possible to open LAS files within MapInfo? If so, how is accomplished in MapInfo 10.0?
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1answer
394 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 ...
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1answer
185 views

How to compare accuracy of two DEM using GRASS

How do I compare accuracy of two DEM data (lidar and srtm) (possibly through rmse) using GRASS GIS? thanks
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1answer
668 views

GDAL RasterIO grabbing memory

I have written an application in c++ to read LiDAR files and convert to various rasters using GDAL; this worked very well on small scale tests (47 LAS files) however, when used on a live task the ...
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1answer
183 views

LiDAR Feature extraction specifications/standards

I have vector data representing forests/trees/buildings that have been automatically extracted from LiDAR data. I am looking for specification/guidance for LiDAR derived products, or any standard for ...
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629 views

Is it possible to load an .las file directly into QGIS? [duplicate]

Is it possible to load an .las file directly into QGIS? I would like to be able to load LiDAR data and to be able to do analysis based various feature attributes; e.g., elevation, classifications, ...
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1answer
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What is the procedure to load LAS files in QGIS 2.0.1?

What is the present procedure to load LAS files in QGIS 2.0.1? After some searching I found a paper outlining the procedure; however, it was for 1.8.something, and related posts here are all rather ...
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2answers
525 views

How do you convert a .lasd (Lidar) coordinate system?

How do you 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.
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339 views

Practical Building Extraction Algorithm Implementation

I've been reading many papers over 3D building extraction using LiDAR data and Aerial images. I see that there are many different algorithms for doing such things, such as this and this. Those ...
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435 views

Lidar data in ArcGIS 10.1

Problem: I have a set of LAS files that doesn't display in Arcmap. Details: I try to use LAS to tin in Arcmap to convert my LAS points to a TIN. However, when browsing to the folder with the files, ...
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1answer
337 views

LAS sample file for electric utility poles

Does anybody know a souce where I can find a sample LAS file that has electric utility poles? Like seen here - http://resources.arcgis.com/en/help/main/10.1/index.html#//015w00000040000000
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2answers
282 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 ...
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795 views

Tool for exporting las data

Is there any tool available for extracting the X, Y and Z channels from a .las file and exporting them to a .csv or similar file?
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512 views

How to develop a Canopy Height Model of LIDAR data in QGIS?

I am having a DTM and DSM files .I want to develope a Canopy Height Model in Qgis is it possible?
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1answer
78 views

rooftop modeling

I´m trying to model building rooftops based on a LiDAR dataset. I've already interpolated using Delaunay's triangulation a DEM with 1m resolution. Due to LiDAR data is not accurate in building edges, ...
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1answer
325 views

Problem reprojecting LIDAR data with Liblas

I am currently trying to reproject a LIDAR file (.las) using the Open-Source LibLAS, compiled on a Scientific Linux server. The Original data is in Oregon Lambert, NAD83 (EPSG:2992), and I am trying ...
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1answer
169 views

Options for manually identifying road defects from Terrestrial Lidar

I am trying to create a process to identify road defects manually from Lidar. We have Erdas 2013, ArcGIS10.1 and Global Mappper 14.2 as options for paid software. So far Merrick Mars displays the ...
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0answers
288 views

Extract road defects from terrestrial LiDAR, in Erdas 2012 or ArcGIS10.1

I'd like to extract road defects from a lidar point cloud. So, wherever a road surface drops or raises by a few mm relative to 100 cm around it. I know it's possible but I just can't find or figure ...
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1answer
1k views

arcpy “The table name is invalid”

I wrote a script that, ideally, loads raw .las (LiDAR data) files into a geodatabase, then creates a terrain from the multipoint files that are created. When I run the script though I get: ...
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Linux alternatives to visualize and analyze LiDAR datasets

For a long time I have been using softwares based in Windows to visualize and analyze LiDAR data sets for forest application. Recently I have started to move all my work to Ubuntu platform, but I'm ...
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2answers
737 views

How do I import UK Environment Agency Lidar data (.asc) into Quantum GIS

I have downloaded Lidar data from the UK Environment Agency as ESRI ASCII files but being a complete novice as far as GIS is concerned I do not know how to view them. Quantum GIS was recommended to me ...
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1answer
214 views

Input data format and read multiple files into Grass 6.4.1

I am trying to read in multiple (hundreds, thousand) LiDAR ascii files into Grass. They contain elevation data. I think I have managed one, and I can make a map of elevations, using File, Import ...
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1answer
615 views

How to repair and clean contours from high data resolution (lidar)?

I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution. The extracted contours have a lot of artifacts like dangles and islands. First I used ...