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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4
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2answers
168 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
174 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 ...
9
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2answers
2k 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. ...
6
votes
2answers
444 views

Normalizing point cloud data

How I can get Digital Height Model (only object heights, DSM - DTM = DHM)? Many applications can do this, but they convert it to GRID or TIN format. I was wondering if it was possible to keep the ...
4
votes
3answers
384 views

LiDAR data density, returns per square meter

How can I compute a raster showing the number of return points per square meter using SAGA GIS or other open source software? My goal is to obtain a mask which would show me the places (cells) ...
13
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3answers
358 views

Account for bridge overpasses in a ground DEM to allow for water flow 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 ...
3
votes
1answer
126 views

What is the status of any ongoing efforts that will allow QGIS to display .las files directly in the main 2D window?

After some research on QGIS's ability to display .las files, I came to the conclusion that it is not possible: currently any attempt at this requires converting .las to .shp as described here and ...
3
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3answers
688 views

How to determine bare earth from unclassified LAS file

I have data in LAS format with RGB values created from Aerial photogrammetry using a UAV. I am trying to find a solution to extract the bare earth to create my DTM from the DSM. I have tried SAGA, ...
4
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2answers
777 views

Comparing two TINs created using ArcGIS for Desktop?

I have the following two files: LiDAR las file1 Let's give it a name LiDAR las file2, contains the same file1 data, where number of points randomly removed. So if file1 contains X number of ...
2
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0answers
329 views

Open-source reader of Leica C10 terrestrial LiDAR proprietary file format

I have a Leica C10 terrestrial LiDAR (laser scanner) system. The system creates and stores point cloud data in a proprietary .bin file. Currently I have to use Leica's proprietary LiDAR software, ...
3
votes
1answer
224 views

Problem with MCC-LiDAR (insufficient memory)

I am running mcc-lidar on a win7 64bits with 16gb of ram. Nevertheless when I try to process a las file with 1, 800 000 points using -s 0.5 and -t 0.3 the program tells me: Error: insufficient ...
8
votes
1answer
354 views

River boundary (bank) extraction from LiDAR

Is there any way to extract a river boundary (bank) from LiDAR data and its products (DEM, intensity image and slope) automatically? Digitizing is very time consuming.
1
vote
2answers
116 views

Cropping aerial image using Python?

How can I crop an area from an aerial image knowing the latitude and longitude of the image's corners and also the cropped section? I have a LiDAR scan and I and want to crop an image overlay to fit ...
5
votes
0answers
235 views

How to compare two sets of points in QGIS?

I have two point layers with XYZ data; one set are points measured in the field and the second set is a Lidar data set. I want to check the accuracy of the Lidar in comparison to the measured data. ...
2
votes
2answers
90 views

Rename las files with Python [closed]

I have a bunch of LAS files that have been delivered with different naming conventions. I want to rename the files to all have the same uniform naming - based on the easting and northing coordinates ...
23
votes
2answers
4k 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, ...
15
votes
11answers
28k views

How to a convert LiDAR XYZ files to DEM / DSM?

Normally consultants (LiDAR survey) provide me with data to my specifications; already in ESRI GRID or ASCII GRID format. This way LiDAR data can be easily used with ArcGIS. This time I only have xyz ...
3
votes
2answers
122 views

How to manipulate lidar map using sun azimuth

Hi I am VERY new to QGIS and am struggling. I have a Lidar map and want to change the view so that the ground shadow is manipulated (looking for archaeological anomalies). I think it is the sun angle ...
5
votes
3answers
884 views

Finding outliers with wrong Z values in LIDAR data

I have more than 2000 XYZ (only ground points) .txt files and I have to do Quality Control (QC). Let's say I have file, which I converted to multipoint (or even singlepart feature). I have mean Z ...
6
votes
1answer
785 views

Breakline detection algorithms for LIDAR dataset

I'm searching for algorithms or open source tools I could use to detect breaklines from a LIDAR dataset; more specifically, from the terrain points of the dataset. At the moment the only thing I've ...
1
vote
1answer
222 views

Volume calculation analysis with Quick Terrain Modeler 8.0.2. (QTM)

I have been unsuccessful in finding a tutorial, guide or example of the 'Volume Calculation' analysis tool in Quick Terrain Modeler. http://appliedimagery.com/ I was wondering if anyone else has any ...
3
votes
1answer
43 views

Algorithm behind custom tool of ArcGIS for Desktop called xyz2grid21?

I am a researcher from Romania and I have used xyz2grid21 ArcGIS tool (by Min-Lang Huang) in order to convert xyz files (LIDAR data) to ASCII and ESRI grid in order to obtain a DTM. I need to know ...
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vote
2answers
213 views

Lidar and infrared data to detect petroleum releases

Would this combo detect differences in soil temperature in proximity to the release due to the higher temperature of pipeline fluids or would the surface temperatures be affected by the volatilization ...
3
votes
1answer
119 views

Convert coordinate system of Lidar or TIN?

I have Lidar data and I want to create a TIN from it, and then run the TIN Triangle tool to create a polygon shapefile of the triangles. The only thing is that the Lidar data is in a UTM CS with ...
3
votes
2answers
463 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, ...
3
votes
1answer
1k views

How to install LAS tools in Processing for QGIS 2.4?

Does anyone know were the processing menu moved in QGIS 2.4? Specifically I am trying to install the Lastools box for QGIS following these instructions. ...
1
vote
1answer
102 views

How to interpret Lidar scan line problems?

I am calculating various gridmetrics using the Lidar processing tools in FUSION. The dataset I am working with contains 154 flight lines of high density data, at a nominal pulse spacing (NPS) of 1.5 ...
7
votes
1answer
225 views

How to decide possible areas for water retention using lidar

I have lidar imagery for a watershed and am trying to process it so that a landowner know if they can hold water on their property or where they can hole the water (this is the more important part). ...
9
votes
2answers
256 views

Aerial LiDAR: What is an acceptable resolution?

I am in the process of initiating a project involving laser scanning. The area to be scanned i s approximately 5000 km². We are initially going to use the data to create a solar potential application, ...
12
votes
4answers
2k views

Comparing two Digital Elevation Models (DEMs) from LAS files?

I have two Lidar las files, one is original let's say with X points. And the other is copy of the first las file but with Y points, where Y is less than X. Now, I want to compare how the Digital ...
2
votes
0answers
136 views

Cloud points metrics with Terrascan

I need to extract from a las file statistics like percentile 95 height and others. Do you know how to do it with Terrascan? I can do it with FUSION, but I would like to do it with Terrascan.
1
vote
1answer
291 views

ArcPy error: Add Feature Class to Terrain. [closed]

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 ...
2
votes
0answers
54 views

Opengeo and Ubuntu memory issue

I was working with LiDAR in Opengeo suite while following the Boundless tutorials (http://workshops.boundlessgeo.com/tutorial-lidar/) In my recent post titled 'LiDAR and Opengeo', I mentioned about ...
0
votes
1answer
185 views

Point cloud LiDAR

I have been trying to grid a point cloud, version1.2, LiDAR datasets which are intended to be used for hydraulic simulation of flood propagation. Already, I have used Arc* to work on the traditional ...
4
votes
0answers
174 views

Has anyone used ArcGIS for 'automatically' detecting lineaments from a high-resolution (1m) DEM?

I have a set of DEM's produced from LIDAR data. I am wondering if anyone is familiar with or knew of any published research papers which looked at (semi-)automatically detecting lineaments /or ...
3
votes
1answer
113 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
votes
1answer
168 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: ...
4
votes
3answers
734 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 ...
1
vote
0answers
21 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
votes
1answer
118 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
votes
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 ...
1
vote
2answers
143 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 ...
1
vote
0answers
116 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
votes
1answer
736 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
votes
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
42 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
votes
0answers
85 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 ...
4
votes
1answer
171 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
245 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 ...