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
96 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 ...
2
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1answer
108 views

When to reproject LAS data?

I've downloaded a few LAS files from the NOAA: http://www.csc.noaa.gov/digitalcoast/data/coastallidar I used lasinfo to get the coordinate system of the LAS files and it returned: ...
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0answers
10 views

Converting SBET (Smoothed best trajectory) files to an ASCII format [duplicate]

I have LiDAR trajectory data in an SBET (Smoothed best trajectory) format, but to the analysis I wish to carry out I need it in an ASCII format. Does anyone know if there's a way to convert it? Thanks ...
4
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3answers
527 views

Las to bare-earth DEM: average points spacing and cell size

I am using ArcGIS 10.1 to generate a DEM (bare earth) from LAS dataset. To accomplish this, I use 'Las Dataset to Raster' tool as described in Esri website. I have read here and there in the web that ...
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0answers
20 views

How can I filter a MultiPoint Z / xyz points against a 2d polygon [duplicate]

I would like to filter point data from LIDAR scans (3d) by parcel plot lines (2d). I began with loading the lidar data into microsoft sql and performing a STIntersects between the MultiPoint and the ...
2
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1answer
100 views

libLAS las2las scrubs ground point data on Ubuntu?

I am trying to use las2las from libLAS on Ubuntu 14.04 entering the following code into the terminal: las2las --input merged.las --output ground.las --keep-class 2 This outputs a LAS file which has ...
5
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3answers
1k 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 ...
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2answers
129 views

Contours from DEM with human features

I am rather new at GIS and I would like to have some guidance on what follows. I have some DEMs derived from LiDAR data. These DEMs contain building and other human features (e.g., roads). I was ...
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0answers
94 views

Adding LAS files (or derivatives of) to mosaic error in ArcGIS

I am trying to add LAS tiles, (or lastools derived .tif or .img tiles of the same LAS tiles) to a mosaic in arc 10.2 and am getting the following errors: Error: 8004201a : Insufficient information ...
0
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1answer
597 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 ...
9
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4answers
1k views

How to distinguish buildings from vegetation in LIDAR data?

In order to extract the vegetation mask in ecognition, with object base analysis, with creation of the rule sets, the buildings were also classified! Any idea how to extract building from vegetation? ...
2
votes
1answer
38 views

Setting Point Cloud Data Colour from Raster

I was reading this article: http://blog.safe.com/2013/10/14-ways-to-take-charge-of-lidar-data/ Number 12 states that you can change the colour of your point-cloud data by using a raster image. Does ...
0
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0answers
71 views

How to build a LAS dataset for simple viewing in Arcgis

I've been given a few LIDAR files to show my boss how useful the data can be. The problem I have is that I simply need to be able to view it using LASTools but I need to build a LAS Dataset first. I ...
8
votes
2answers
2k views

Workflow for determining stream gradient?

As far as data goes, I'm working with NHD .shp files, 10m DEMs, and some LIDAR data. My goal is to determine gradient for 100m segments of a network of streams. I'm already able to do this, but I ...
7
votes
8answers
6k views

Where can I get pointcloud data?

Is there any freely available pointcloud data? I'm especially interested in dense clouds of small areas(5m to 100m radius) but anything else would be fine too. Edit: I've found that these pages ...
4
votes
1answer
143 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 ...
4
votes
1answer
188 views

How to automatically check for lidar flight line overlaps?

I have a series of lidar-based raster products created via FUSION. Since I am working with low density lidar data, many of the raster images show significant striping where lidar returns overlap on ...
0
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1answer
249 views

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 ...
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0answers
102 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 ...
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0answers
62 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 ...
0
votes
1answer
240 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 ...
7
votes
1answer
1k 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, ...
2
votes
1answer
534 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
103 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 ...
5
votes
2answers
388 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 ...
2
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0answers
74 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 ...
1
vote
1answer
103 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 ...
2
votes
0answers
89 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 ...
11
votes
3answers
513 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 ...
5
votes
2answers
276 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 ...
1
vote
1answer
112 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.
0
votes
1answer
314 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 ...
0
votes
1answer
225 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
votes
5answers
4k 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.
4
votes
1answer
776 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 ...
7
votes
1answer
164 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
votes
1answer
101 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
votes
1answer
140 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 ...
3
votes
0answers
103 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 ...
4
votes
1answer
136 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 ...
1
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0answers
34 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
vote
1answer
143 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 ...
2
votes
2answers
637 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
votes
2answers
284 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
vote
1answer
192 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 ...
1
vote
1answer
169 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
1
vote
2answers
752 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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0answers
34 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
votes
1answer
174 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 ...
4
votes
1answer
1k views

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 ...