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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24
votes
12answers
15k views

Working with LiDAR data using other than Esri software?

I will be working with LiDAR data soon and I am wondering what the alternatives to using Esri software to do this are, including open source solutions?
24
votes
2answers
6k 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, ...
18
votes
7answers
10k views

Methodology for creating accurate drainage networks (and catchments) from high resolution LiDAR DEM?

This is not the first time I've stumbled over this issue; it seems that I am unable to generate a correct drainage network model and the resulting catchments from full resolution (1m cells) LiDAR ...
15
votes
10answers
31k 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 ...
14
votes
3answers
482 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 ...
14
votes
6answers
1k views

Ways to visualize multiple large LIDAR tiles?

I want to load approximately 10 large LIDAR tiles for analysis. I have tried using ArcScene but it appears there is a limit on how much data ArcScene can handle at one time. Each tile is 65-90MB in ...
13
votes
5answers
841 views

Dikes extraction from DEM

I do have DEM of 1x1 meter and original LiDAR point cloud in .las, that DEM is made of. I need to extract river dikes (highest points of the dikes) to vector feature (point, polyline). Any idea for ...
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 ...
12
votes
3answers
2k views

Optimize nearest neighbor query on 70 million point cloud on SQL Server 2008

I have about 75 million records in a SQL Server 2008 R2 Express database. Each is a lat long corresponding to some value. The table has geography column. I am trying to find one nearest neighbor for a ...
12
votes
2answers
799 views

PostGIS interpolation / triangulation options

I'm looking for an open source workflow to automate DEM construction. We have a series of sites that fall within a LIDAR dataset. We want to create site specific DEM's for each site, and we're ...
11
votes
3answers
995 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 ...
10
votes
5answers
1k views

Processing full-waveform LiDAR?

Does anyone know of a good software package for processing full-waveform lidar? Also, does anyone know of a good tutorial on processing full-waveform lidar?
10
votes
6answers
4k views

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 ...
9
votes
9answers
11k 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 ...
9
votes
3answers
445 views

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

From time to time, we use LiDAR data for modelling in ArcGIS. Previously, we would be supplied either an .xyz or .ascii of the data, but more recently, we are also being provided .las files in ...
9
votes
2answers
1k views

Combining high resolution and generalized hillshade rasters to produce enhanced shaded relief?

I often add LiDAR data to a map along with a shaded relief. Most of the time I have to generalize the LiDAR DEM depending on the scale of the map. Still, there is often too much detail and mountain ...
9
votes
3answers
5k views

Best method to aggregate 1m DEM mosaic to 10m DEM

I have a mosaic of a 1m LiDar derived DEM. I need to output a subset of the data as a 10m DEM. I am currently using the aggregate tool in ARCGIS 10 to produce a mean value for each new 10m pixel. ...
9
votes
2answers
221 views

Cleaning blocks pattern from urban LIDAR (blocks uplifted from streets)

We have a 1-meter LIDAR DEM from a city. A small subset can be downloaded from this link: This screenshot shows raw DEM with gray palette (darker belts are streets, and greyish and whitish ...
9
votes
3answers
350 views

Costs and requisites when hiring aerial LiDAR survey [closed]

My organization is considering hiring a company to capture new LiDAR data to help with current stormwater issues that we are currently experiencing. I am a GIS analyst that has been assigned with this ...
9
votes
4answers
2k 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? ...
9
votes
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. ...
9
votes
2answers
279 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, ...
8
votes
2answers
3k 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 ...
8
votes
4answers
3k 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, ...
8
votes
2answers
1k views

What are LiDAR returns?

Can someone help with an explanation and some references, in order to understand the nature of return pulses within a LiDAR system.
8
votes
3answers
2k views

Do any open-source .Net libraries (commercially usable) exist for reading/writing LiDAR data?

I have a few LiDAR point data (.las files) with me. I would like to read the X,Y and Z from it using .Net. I found liblas, which is in C++ and I am not sure if it can be used commercially after ...
8
votes
1answer
2k 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, ...
8
votes
1answer
426 views

How to georeference LAS files?

First of all, I am a newbie in GIS. I have a lidar point cloud with GPS and telemetry data associated. Then, I transform coordinates of every point to an ECEF coordinate system and finally I ...
8
votes
2answers
412 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 ...
8
votes
1answer
466 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.
7
votes
3answers
530 views

Filtering out canopies and buildings from DSM to have a bare earth elevation

Can anyone suggest methods in filtering out trees and buildings from a DSM so as to come up with a reliable DEM? What I have is a grid from a LIDAR data (.tif file, with 1m resolution). I was going ...
7
votes
2answers
158 views

Are PDAL or PCL capable of producing LiDAR grid metrics?

I typically use Windows-based FUSION to generate grid metrics, which can be used to describe forest structural characteristics. From the FUSION documentation: GridMetrics computes a series of ...
7
votes
3answers
2k views

How to make 3D building models from lidar data in ArcGIS?

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 ...
7
votes
1answer
529 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 ...
7
votes
1answer
238 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). ...
7
votes
1answer
5k views

Building extraction with LiDAR data (Improve Process)

I have the following process for automatically creating building outlines/footprints from Las files and was wondering if anyone can help improve it or has suggestions for other processes to use? ...
7
votes
1answer
146 views

Extracting wall information using LIDAR data?

I'm trying to extract wall using the LIDAR. I have tried Fusion, Whitebox, Lastools in Arcgis, Saga and Envi. Those are tools that I can use. The walls I am interested are mainly 1 meter high. Some of ...
7
votes
3answers
509 views

Grass v.rast.stats returning null values

I have a vector layer (polygon) and a raster layer. The raster layer holds values for height above bald earth in a field called "value". I'd like the vector layer to inherit either the mean or the ...
7
votes
3answers
240 views

Extract DEM and DTM information from LIDAR image using E-Cognition

I´m trying to extract DEM and DTM from a LIDAR file. Currently, I rasterize the image but don´t know which algorithm I need to apply to obtain the DEM and DTM information in different models to be ...
7
votes
1answer
186 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 ...
6
votes
3answers
893 views

Assigning RGB values from Geotiff image to LiDAR data, using R

I have given a Geotiff image and its corresponding Lidar data (x,y,z) in UTM coordinates. I need to merge the Lidar data with the RGB values from the image. That means, at the end, I need to plot ...
6
votes
2answers
684 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
votes
3answers
10k views

Viewing .las format LIDAR data in QGIS?

Is there an easy path to visualizing this LIDAR data? I have QGIS, and some USGS LIDAR data in (.las) format downloaded from http://lidar.cr.usgs.gov/ . This means I have both the (.las) and ...
6
votes
3answers
2k views

Can I use LASTools to classify point data?

I am presently using LAStools to analyse LiDAR data. Can LAStools classify the points into various features such as vegetation, roads, buildings etc? If so, how is it done?
6
votes
5answers
5k views

Easy way to create a boundary polygon shapefile from a set of LAS files using ArcGIS 10?

I have a bunch of LAS file sets that I need to process. The current task at hand is to generate a "footprint" shapefile that contains polygons for each LAS tile. I am looking for a graceful way to ...
6
votes
1answer
1k views

How to display dynamic raster (lidar) data on a Web map?

I have some high quality LiDAR data. I need to process it dynamically, and update a field (not elevation field) depending on my input and elevation at that point. Once this is done, I need to display ...
6
votes
2answers
654 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 ...
6
votes
1answer
923 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 ...
6
votes
1answer
436 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 ...
5
votes
3answers
312 views

Thinning large LiDAR point cloud?

I have a large point cloud (LAS file) and I am trying to thin this using a complex technique. I know it is possible to thin a point cloud using simple techniques such as extracting every nth point. ...