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

0
votes
1answer
8 views

Can't normalize LiDAR point cloud with lasheight and -replace z (LAStools)

When I try to use lasheight with -replace z to normalize the point cloud, the height of points are changed (destroyed heights; see pictures below). Without using -replace z everything is ok, but the ...
1
vote
0answers
15 views

Can I use georeferenced jpeg raster as map layer in GeoJSON.io?

Can I use georeferenced .jpeg raster as map layer in GeoJSON.io? I thought that I could, but it doesn't work. I converted .tif raster visualization of LiDAR data to georeferenced jpeg. After this, I ...
0
votes
0answers
12 views

Create 1' Contours Using Bare Earth Lidar .XYZI Point Data

I have 42 tiles of Lidar .XYZI point data containing approximately 800,000 points each and i need to create 1' contours out of the data. I have access to ArcMAP 10.3 and the 3D Analyst and Spatial ...
1
vote
1answer
18 views

Filtering LiDAR data with las2las by scan angle range?

I am using las2las to filter .las data and I would like to filter the data between a scan angle of -15:+15; however the algorithm tells me the following: ? error bad lexical cast: source type ...
2
votes
1answer
19 views

Building height in OpenStreetMap

I was wondering if there are some free projects which enable extracting the building height information from openstreetmap data? I downloaded data for a couple of large cities (Manhattan island, ...
0
votes
0answers
28 views

Representing multiple polylines in unique vector layer?

I have imported a layer which contains a lot of lines. They overlap each other in a cross kind of pattern. When zoomed out it can look like this: When zooming in on one of the broader lines it ...
1
vote
1answer
38 views

Free high resolution DEM or Lidar data for St Lucia

I found the 30m Aster DEM for St Lucia, but am wondering if there is some DEM or other elevation data source (Lidar) with a higher resolution. I googled, but have been unsuccessful in finding any free ...
2
votes
1answer
24 views

Update EVLR header info for .LAS file using laspy

I'm trying to change the header info for a LAS file using the python 2.7 (64-bit) laspy module (version 1.2.5). I'm attempting to follow the example shown here (in the section "Writing Data + EVLRS"): ...
1
vote
0answers
106 views

Difference in the elevations for the same building on two DSMs saved in *.asc and *.laz formats

The following question concern the same type of data as the one I've asked in Differences in the longitude and latitude between a LiDAR DSM and an optical image. Basically, I've downloaded a tile of ...
2
votes
1answer
38 views

Recording height profile from raster along a polyline shapefile?

I'm looking for the easiest way to record a series of raster values along a 400 meter transect in ArcGIS 10.3.1. I'm working with a LiDAR canopy height model with 3mx3m cells where each cell ...
3
votes
0answers
64 views

Visualizing elevation profile across a whole mosaic dataset?

I'm working with many DEMs derived from LiDAR data (IMG format) in a mosaic dataset. This allows me to create hillshade (or shaded relief) functions to display the data, which is great. However it ...
1
vote
0answers
39 views

Creating 3D interactive model from lidar data using ArcGIS for Desktop? [duplicate]

I have a couple of las files for a city and I need to make a 3D model of the buildings, which should display info about the building when clicked on. I am pretty new to ArcGIS so I don't have the best ...
0
votes
3answers
125 views

Assigning class codes for LAS files? [duplicate]

I have LAS files with code 0 - never classified. I have no other classes other than this. How do I assign class codes for my LAS file?
0
votes
0answers
27 views

How to generate DTM from LiDAR point cloud data? [duplicate]

I have LiDAR point cloud data (X Y Z Intensity), and I want to generate DTM (only ground point). Is there any solution (algorithm or software)?
3
votes
1answer
52 views

Differences in the longitude and latitude between a LiDAR DSM and an optical image

I've downloaded the UK's LiDAR elevation data (see below) in laz format for a specific region (Tewkesbury) from: http://environment.data.gov.uk/ds/survey#/download From that, a DSM (Digital Surface ...
1
vote
0answers
54 views

Thinning LiDAR points to remove redundant neighbors?

I'm trying to develop a workflow in ArcGIS with 3D Analyst or Spatial Analyst to intelligently thin a grid of spot elevation points created from a LiDAR DEM. The current point spacing is 1 meter. Some ...
5
votes
1answer
204 views

Generating surfaces of different heights from LIDAR points

I am seeking a way to generate surfaces (polygons in a 3D space) of different heights from LIDAR point clouds, whose spacing is 4 points per square meter. The typical application is like roofs, which ...
0
votes
0answers
37 views

Matching drone point cloud data with original lidar survey? [duplicate]

I have point cloud data collected from a drone of a particular area. I too have the point cloud data collected from the lidar survey. Both are georeferenced. Now, I need to match the point cloud data ...
2
votes
2answers
80 views

Pixelated DSM using LAS Dataset to Raster?

I am using ArcGIS 10.2.2, and I am trying to create a DSM out of some LIDAR data. After checking the LAS Dataset properties, I see that I have an average point spacing of approx 0.3. I tried ...
2
votes
1answer
46 views

Assigning CRS using las2las from libLAS?

My las file had a spatial reference of "None." I tried to assign the CRS (in which data were collected) with the following command line: las2las flightline_002.las --a_srs EPSG:32632 lasinfo --no-...
3
votes
2answers
143 views

Adding LAS files into AutoCAD map 3D with Point Cloud Manager tool

It's my first time to use AutoCAD map 3D for LiDAR. Based on my googling, it is said that I can bring .las file by creating new index and using the Point Cloud Manager tool (the image on the top - ...
5
votes
2answers
101 views

Improve DTM under forested areas without smoothing?

I'm using a DTM retrieved from LiDAR data and I noticed that forested areas are grainy or not defined. The DTM data was retrieved from geostore.com. Here is one example: Is there any way to ...
4
votes
0answers
56 views

Why do first returns have more blanks than last returns in LiDAR data? [closed]

I'm working on an ASCII LiDAR file that has the first and last pulse returns included. Can anyone tell me why a first pulse return may come back with more blank spaces in the data than a last pulse ...
0
votes
0answers
26 views

Activating LAStools - 'wrong value for parameter “Msys folder”' [duplicate]

Whenever I try to activate LAStools, I get the following error, despite setting the path as /Users/grant/LAStools/ - which is its actual location: Wrong value for parameter "Msys folder": ...
3
votes
1answer
492 views

QGIS 2.14.1 LAStools install error: “wrong value for parameter 'Msys folder'…”

I went to step 4 from rapidlasso.com guide and extracted LAStools to my C drive and just made the folder there. I can't do step 8 because it seems to already be in "advanced interface". Then, step 9 ...
1
vote
0answers
74 views

Classifying building walls from LiDAR point cloud [closed]

I am currently working on mobile point clouds in order to extract 3D building models in the residential area. I could successfully classify ground, vegetation and building roof lines, but still have ...
2
votes
1answer
45 views

Reverse colour-ramped DEM to its original elevation value?

A have a GeoTIFF LIDAR image which display DEM in its color-ramp version (color relief) from blue (minimum value) to red (maximum value) and green (in between). I don't have the original elevation ...
4
votes
2answers
158 views

Options for visualizing LiDAR data on (Mac) OS X?

I've recently come across open data LiDAR files for the city of Vancouver. I'd like to view it on my Mac (2011. 10.6.6 OS). My intention is to use the LAS file to identify what the tallest trees are ...
4
votes
1answer
78 views

30m/10m/1m resolution DEM for microtopography research

I am conducting research in a region of Illinois that does not have a LiDAR dataset. I am looking to develop a fine scale habitat species distribution model; however, the coarse data available (30m/...
4
votes
0answers
49 views

How to get NIR values into a LAS file then a CSV?

We are trying to deliver a LAS file with NIR values added for each point. The NIR comes from a raster captured at the same moment as the LiDAR, and is stored as an 8bit number along with RGB in 8bit. ...
3
votes
2answers
102 views

Classifying raw LAS data as bare earth in ArcGIS for Desktop?

I have a raw LAS data that has only one return (no second/ third.. return) and not classified yet. The only information I have is intensity and elevation. Is there any way that I can classify bare ...
3
votes
2answers
198 views

Converting LAS to DWG/DXF using open-source software?

Is there a way to convert LAS point clouds to DWG and/or DXF files using open source software? Also willing to script with Python - is this possible using libLAS/LASlib for example?
3
votes
1answer
38 views

Do outputs (shp, dwg) inherit vertical datum from input (las) files?

I'm working in ArcMap. I pulled LiDAR data off earth explorer and created a DEM with the LiDAR data. I then created contours as a SHP file and exported to DWG (CAD). I was asked if the CAD file's ...
0
votes
3answers
93 views

Extracting impervious areas (buildings, rails, pavements) from LAS dataset [closed]

How to extract impervious areas (like buildings, rails, pavements etc.) from las dataset and receive it like a raster? I tried to do it with intensity, but there are many valids with vegetation. I ...
4
votes
2answers
584 views

Converting LiDAR files from LAZ to LAS format

I'm trying to convert LiDAR files from the LAZ format (the compressed version) into LAS (the uncompressed version) using LASzip software. However, I am not really sure how it works. I created a new ...
5
votes
2answers
123 views

GRASS r.in.lidar tool generates incomplete rasters

I have been trying to import a huge LIDAR file (10.5) Gb to GRASS GIS using r.in.lidar. It does the task, but only for part of the image, as shown below: Canopy Height Model (CHM) generated with ...
1
vote
1answer
76 views

Extracting above ground features from unclassified LAS [closed]

What's the best way to vectorize features from LAS? I have "Classified" LAS files, however they were never processed for classification. Thus of 181 million points (9 tile sample) about 60% are class ...
1
vote
1answer
47 views

How to specify LAS dataset filters in ArcMap ModelBuilder?

I'm trying to create a tool in the ArcMap ModelBuilder to extract a canopy height raster from LiDAR data. I need to create rasters for ground elevation and first return. I've got my LAS dataset, and ...
3
votes
1answer
46 views

How does the offset values of LAS files relate to their coordinate system?

I have a conundrum concerning LiDAR data, the stored point offset, and the coordinate system. I process large amounts of LAS data in TerraScan (TS), which sits on top of Microstation (MS). I receive ...
3
votes
1answer
139 views

Converting between coordinate systems for LAS file using LASPY

I am trying to convert a .las file from WGS84 to UTM17. I have some drone imagery that was used to generate a 3d point cloud/ .las file, but it is in latitude/ longitude instead of easting/ northing. ...
1
vote
3answers
209 views

Classifying individual trees from labelled LiDAR point cloud [duplicate]

I have a classified point cloud for an area of 250*250 square meter, with 1 meter resolution. It has a 5 lakhs points with an average point density of 9 (means around 9 points within a pixel). I ...
1
vote
1answer
296 views

LAStools in QGIS error at activation: “wrong value for parameter 'OTB applications folder'…”

I have a problem with LAStools in QGIS 2.14. I've followed the LAStools instructions for downloading LAStools for QGIS. ` I replaced 'lidar' folder in C:\OSGeo4W64\apps\qgis\python\plugins\processing\...
3
votes
2answers
160 views

Retrieving LiDAR metrics from relative vertical layers of point cloud

I need to obtain the proportion of all returns within 5 equally spaced height bins between the cutoff (1 meter) and the maximum height value. I need to get this proportion of all returns for 1000 ...
2
votes
1answer
83 views

Extract manhole covers from ground LiDAR

I am wondering if anyone has come up with an automated or semi-automated workflow for extracting manhole covers from LiDAR data in ArcGIS? I was thinking about looking at the change in elevation ...
5
votes
2answers
105 views

DEM out of a shaded relief LiDAR?

I have a DEM built from LiDAR data and the file extension is .tif. When I open this file in ArcMap it seems to be a shaded relief DEM (see the screenshot below). It happens I want to visualize the ...
4
votes
1answer
124 views

Importing LAS files in QGIS with LAStools gives an 'ascii encode error'

I'm new to QGIS environment and I am trying to load LAS files into QGIS with lasground but when I run the following process an error occurs: 'ascii' codec can't encode character u'\u0105' in ...
1
vote
1answer
115 views

Shifting LiDAR point clouds that have been incorrectly georeferenced

I am new to LiDAR and have never been a part of the LiDAR data pre-processing stage and hence, this question. I have two LiDAR point clouds (.las files) of a densely forested area that were captured ...
1
vote
0answers
77 views

Reduce Z value precision in QGIS

The .asc LiDAR files provided by the environment agency have height values provided to a precision of the level used to measure atoms. How to quickly lose a few of the pointless digits on the end to ...
5
votes
2answers
158 views

Can LiDAR differentiate between rock and soil?

Can LIDAR by itself, tell the difference between rock (large and small) and soil? I'm under the assumption that the answer is no. However, I wanted to check here with the experts as I was told by ...
0
votes
1answer
31 views

Fixing Pixelation in DSM [duplicate]

I ran las dataset, then las to raster using max for DSM. Two and a half hours later I have 3 areas showing pixilation using higher level coloring. See enclosed image. I found on web that seamless ...