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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2
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2answers
106 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 ...
7
votes
3answers
2k 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
145 views

What is the definition of pt_spacing on Point File Information tool?

I can't find any definition for the outputs of Point File Information tool (3D analyst), specifically the pt_spacing field. Is this the average distance between points, or the average number of ...
2
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0answers
75 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 ...
2
votes
1answer
165 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
106 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 ...
5
votes
1answer
115 views

Making a 3D map with shapefiles, lidar and aerial image data

I want to try to make a simple 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. ...
2
votes
1answer
128 views

Laz LiDAR files display extremely long thin line of points

I am having difficulty properly visualizing aerial LIDAR data from the csc.noaa.gov source. Taking any of the .laz files, the point cloud displays as an extremely long thin line of points. Zoomed in, ...
4
votes
1answer
148 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
114 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.
5
votes
2answers
297 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 ...
0
votes
1answer
342 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
246 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 ...
23
votes
2answers
3k 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, ...
4
votes
1answer
843 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 ...
5
votes
2answers
425 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
votes
1answer
105 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
149 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 ...
9
votes
5answers
2k 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 ...
3
votes
0answers
104 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
145 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
36 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
145 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 ...
3
votes
2answers
310 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 ...
11
votes
3answers
549 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 ...
2
votes
1answer
301 views

Load LAS files in MapInfo

Is it possible to open LAS files within MapInfo? If so, how is accomplished in MapInfo 10.0?
7
votes
1answer
390 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 ...
1
vote
1answer
180 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
0
votes
1answer
641 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 ...
5
votes
1answer
180 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 ...
0
votes
1answer
613 views

Is it possible to load an .las file directly into QGIS? [duplicate]

Is it possible to load an .las file directly into QGIS? I would like to be able to load LiDAR data and to be able to do analysis based various feature attributes; e.g., elevation, classifications, ...
5
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 ...
1
vote
2answers
497 views

How do you convert a .lasd (Lidar) coordinate system?

How do you change a coordinate system for a .lasd (Lidar) dataset? The file is currently in UTM_Zone _15N and I am trying to convert it to IL_East.
7
votes
2answers
338 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 ...
3
votes
2answers
423 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, ...
2
votes
1answer
323 views

LAS sample file for electric utility poles

Does anybody know a souce where I can find a sample LAS file that has electric utility poles? Like seen here - http://resources.arcgis.com/en/help/main/10.1/index.html#//015w00000040000000
4
votes
2answers
276 views

Creating planes, eg roof surfaces, from LiDAR/DSM data

I am capturing the area of roof tops of buildings from a DSM (derived from LiDAR data) which has not been much of a problem. I can then also derive angle, hillshade and aspect but it is only ...
1
vote
2answers
753 views

Tool for exporting las data

Is there any tool available for extracting the X, Y and Z channels from a .las file and exporting them to a .csv or similar file?
1
vote
2answers
504 views

How to develop a Canopy Height Model of LIDAR data in QGIS?

I am having a DTM and DSM files .I want to develope a Canopy Height Model in Qgis is it possible?
1
vote
1answer
77 views

rooftop modeling

I´m trying to model building rooftops based on a LiDAR dataset. I've already interpolated using Delaunay's triangulation a DEM with 1m resolution. Due to LiDAR data is not accurate in building edges, ...
6
votes
1answer
318 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 ...
7
votes
1answer
168 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 ...
1
vote
0answers
283 views

Feature Extraction from LiDAR in Erdas 2012 or ArcGIS10.1

I know it's possible but I just can't find or figure out a workflow for it. Erdas Webinars has the workflow for ver 2011 but this is very different in 2013 as it uses a raster img file instead. I ...
4
votes
1answer
970 views

arcpy “The table name is invalid”

I wrote a script that, ideally, loads raw .las (LiDAR data) files into a geodatabase, then creates a terrain from the multipoint files that are created. When I run the script though I get: ...
5
votes
1answer
1k views

Linux alternatives to visualize and analyze LiDAR datasets

For a long time I have been using softwares based in Windows to visualize and analyze LiDAR data sets for forest application. Recently I have started to move all my work to Ubuntu platform, but I'm ...
2
votes
2answers
720 views

How do I import UK Environment Agency Lidar data (.asc) into Quantum GIS

I have downloaded Lidar data from the UK Environment Agency as ESRI ASCII files but being a complete novice as far as GIS is concerned I do not know how to view them. Quantum GIS was recommended to me ...
1
vote
1answer
207 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 ...
4
votes
1answer
602 views

How to repair and clean contours from high data resolution (lidar)?

I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution. The extracted contours have a lot of artifacts like dangles and islands. First I used ...
7
votes
1answer
216 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). ...
3
votes
1answer
212 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 ...