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.

learn more… | top users | synonyms

1
vote
0answers
21 views

Count trees with SAGA GIS? [on hold]

I have a problem when I try to input A as dsm and b as dem. I followed the steps in this blog http://dominoc925.blogspot.com/2012/02/simple-method-to-count-trees-using-saga.html In grid difference > ...
1
vote
1answer
22 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 ...
2
votes
1answer
29 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 ...
2
votes
2answers
66 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 ...
3
votes
1answer
37 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 ...
2
votes
2answers
95 views

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

Can anyone suggest methods in filtering out trees and buildings from a DEM so as to come up with a reliable DTM? What I have is a grid from a LIDAR data. I was going to clean out the unnecessary ...
2
votes
1answer
76 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
0answers
51 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
47 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 ...
3
votes
2answers
99 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) ...
0
votes
0answers
23 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 ...
2
votes
1answer
63 views

Lidar and Opengeo suite

Opengeo suite has provided a tutorial on how to manage LiDAR data using postgresql. I was trying to follow the tutorial in this link (http://workshops.boundlessgeo.com/tutorial-lidar/). I am new to ...
2
votes
0answers
27 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 ...
-1
votes
1answer
71 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 ...
1
vote
2answers
137 views

Merging multiple rasters with SAME spatial extent

So I began with lidar elevation data 1m resolution, and I performed a terrain analysis to extract specific ranges of elevation from the raster (1st picture is 0-1m elevation, 2nd picture is 1-2m ...
2
votes
1answer
44 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: ...
1
vote
2answers
115 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 ...
0
votes
0answers
8 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 ...
3
votes
3answers
196 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
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 ...
1
vote
2answers
84 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, ...
2
votes
1answer
64 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 ...
1
vote
2answers
95 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
41 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 ...
2
votes
1answer
33 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 ...
2
votes
1answer
45 views

Correcting Classification for LIDAR - ArcGIS

Is there any procedure to automatically correct lidar classification? My LAS Dataset has water listed as ground and buildings listed as vegetation etc... Just wondering if there is any option to fix ...
0
votes
0answers
51 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 ...
1
vote
1answer
44 views

Make a Ground Mask raster with the Greater Than tool (DEMs are generated from LiDAR)

I'm trying to see if I can replicate the Esri solar suitability site example from this article. I fail on the creation of the binary ground raster. I have made a Bare Earth raster from LiDAR ground ...
4
votes
1answer
83 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
votes
1answer
78 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 ...
10
votes
2answers
168 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 ...
1
vote
0answers
81 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
votes
1answer
79 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 ...
1
vote
0answers
39 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 ...
1
vote
1answer
233 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
3answers
109 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 ...
2
votes
0answers
56 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 ...
3
votes
2answers
341 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 ...
7
votes
1answer
644 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
2answers
79 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 ...
0
votes
0answers
31 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 ...
6
votes
4answers
562 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, ...
1
vote
1answer
113 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 ...
2
votes
0answers
67 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 ...
0
votes
0answers
70 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? ...
1
vote
1answer
82 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
79 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 ...
2
votes
1answer
67 views

Las 1.2 format displays extremely long thin line of points

I am having difficulty properly visualizing aerial LIDAR data from the following source: http://csc.noaa.gov/htdata/lidar1_z/geoid12a/data/1124/ Taking any of the laz files, the point cloud displays ...
4
votes
1answer
102 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 ...
1
vote
1answer
95 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.