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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How to remove pixel values below 0 in Digital Elevation Model in ArcGIS?

I made a DEM layer from LAS file (LiDAR).Now for showing a map I have a map like the image below! I wonder how can I remove black area? They have the value -2 to 16! How is possible to set the value ...
4
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1answer
75 views

Account for bridge overpasses in a ground DEM to allow for water flow under the under the overpass

I have a bare earth DEM made from lidar data (A). It works well and has passed all accuracy tests. It is used in storm surge models. The problem we are having is on underpasses. I need to allow water ...
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8answers
6k views

What are best alternatives to Esri software for LIDAR data?

I will be working with LIDAR data soon and am wondering what are the best alternatives to Esri software in your opinion? Which are generally considered to be the tops and flops of the LIDAR Sofware ...
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66 views

LIDAR Dataset displaying 500,000 meters to the East of correct position

First post on here.. I've been hung up for a couple days. Why does my LIDAR dataset show up ~500,000meters to the east of the correct position even though a spatial reference/coordinate system is ...
2
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1answer
120 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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42 views

Elevation maps from point clouds: TPS vs. what other methods

In the reply to another question, @thehealingprocess refers to "...a comparison of interpolation methods for interpolating elevation maps from LiDAR clouds, and in almost all scenarios thin ...
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0answers
17 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 ...
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1answer
200 views

Why does ArcGIS model not recognize Z value column?

My ArcGIS model used to handle .XYZ files well, but now it fails to recognize Z-value column as such - it either recognise no field at all, or it offers some defaults such as "OID". Since the last ...
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1answer
429 views

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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2answers
129 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 ...
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0answers
41 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 ...
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1answer
67 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 ...
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2answers
72 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 ...
4
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0answers
65 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 ...
2
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2answers
60 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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0answers
25 views

How to best alter surface from LIDAR for designing low water crossing and its approaches?

I was wondering if you might be willing to help me work out the best way to use LiDAR data for my thesis project. It involves altering the terrain to add low water crossings at various angles and ...
4
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2answers
152 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 ...
6
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4answers
234 views

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
40 views

3D Analyst - Point File Information - pt_spacing definition?

I can't find any definition of the outputs of the Point File Information tool, specifically the pt_spacing field. Is this the average distance between points, or the average number of points per ...
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3answers
939 views

How to make 3D building models from lidar data?

I have Lidar data, ground points and first returns. I have processed it and have ready tiles from which I am trying to build 3D building models. So far I was able to just extrude the buildings in ...
2
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0answers
61 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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54 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
63 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 ...
7
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3answers
478 views

How to view LiDAR data from a 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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59 views

Making a simple 3D map for browsers with my current geodata

I want to try to make a 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. LIDAR ...
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3answers
229 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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2answers
106 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
72 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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1answer
66 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
65 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 ...
2
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6answers
2k 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. Thanks.
7
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215 views

Looking for free / opensource 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 opensource/free lidar viewer that I can integrate with ...
3
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1answer
119 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 ...
6
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1answer
125 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 ...
2
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1answer
68 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 ...
4
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1answer
63 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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207 views

ArcPy error: Add Feature Class to Terrain.

I'm writing a script to convert lidar data (in .las format) into a terrain without going through all the clicking and so I can send it out to neighboring states with similar programs (I'm using ArcGIS ...
3
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0answers
58 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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61 views

What is important when applying contour with barriers on LiDAR data?

I want to produce high quality DTM from 1 meter resolution LiDAR data and I have a terraced and retaining walls layer to use as barriers. I assume the features at the barrier layer shouldn't be longer ...
4
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1answer
58 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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0answers
26 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 ...
1
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1answer
67 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
448 views

Are there any open source software for obtaining and processing data from the Velodyne HDL-32E lidar?

Does anybody know if a FOSS package exists? The best I could find are the scripts at binarymillenium. I was just hoping somebody here knows of a complete package for obtaining and processing the data. ...
3
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2answers
101 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 ...
1
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1answer
85 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
94 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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2answers
599 views

Mosaicing LIDAR files in ArcGIS 10

I have a number of LIDAR files (the extension is .adf). When put together, they show the same area (each shows one part of it), so, before I do anything else with them, I would like to combine them ...
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258 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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27 views

Why does ArcGIS Publisher appear to mirror ecw Lidar files on southern axis of file?

ArcGIS Publisher appears to be mirroring the ecw Lidar files on the southern axis of the file. Has anyone experience this? Is there a setting in ArcGIS Publisher that I need to turn on or off? The way ...
5
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1answer
125 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 ...