Questions tagged [lidar]

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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1answer
342 views

Difference between files of extension .asc, .asc.aux.xml, .aux and .rrd?

I have received ASCII data from a client. These ASCII files have been created from LiDAR data. For each tile there are 4 different file types: Filename.asc Filename.asc.aux.xml Filename.aux ...
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0answers
52 views

Checking and enforcing downstream Z constraint for synthetic streams?

Assume I've delineated planar (X, Y) stream breaklines to use them for enforcement of bare ground DEM derivation from high density lidar data. The stream features are in a Z and M enabled polyline ...
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1answer
443 views

Laspy exception: “Invalid format”

I am attempting to open a couple of las files in laspy, however one of them has file version 6.0 (although it does not show up as such in lasinfo - I may be missing something). Digging through the ...
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1answer
124 views

PDAL: Argument references invalid/unused stage: 'filters.voxelgrid'

I am running into an error when running pdal translate on Mac OS High Sierra: PDAL: Argument references invalid/unused stage: 'filters.voxelgrid'. This is the command I am using based on a PDAL ...
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2answers
239 views

Interpolating LiDAR scattered ground data?

I wonder if someone can give me a hint on how to interpolate sparse data. I have a 1km by 1km tile located in a dense rain forest area. Original LiDAR data are 37,395,021 points. I have played with ...
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0answers
466 views

Generate Height map for unity-3D from Lidar point data [closed]

I have Downloaded a data set from udacity open source self driving car program from here. It is a ROS (Robotic operating system) BAG file more info.The BAG file contains data collected from Velodyne ...
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2answers
122 views

Finding pixels in DEM with 5% slope or less? [closed]

I am trying to determine if a given property may be amenable for a ground based commercial solar project. Among basic requirements there is flatness (5% slope or less), so I am trying to determine ...
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1answer
33 views

SPDLib spdinterp Error: Two file paths should have been specified (e.g., Input and Output)

I am using spdinterp from the SPDlib to produce a digital terrain model using the following command: spdinterp --dtm --topo -r 50 -c 50 --overlap 10 -i NATURAL_NEIGHBOR -f HFA -b 1 /Users/aaron/data/...
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0answers
74 views

Filtering LAS Dataset and using output for raster conversion? [duplicate]

I have problems with filtering LiDAR data within geoprocessing tools and python scripts. It simply doesn't work despite everyting looks correct. Filtering works only when I apply filter in properties ...
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1answer
1k views

Converting LiDAR .las to .xyz with LAStools outputs incorrect projected coordinates?

I have an application that can import terrain data in an XYZ text format where X = latitude, Y = longitude and Z = elevation. I am trying to convert a LiDAR .las file to this format using las2las. ...
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1answer
113 views

Batch ENVI IDL PointCloudFeatureExtraction results in unprocessed areas [closed]

I have an IDL-ENVI code to batch PointCloudFeatureExtraction for lidar tiles across a large area, however, when run, the output results in lower areas of each tile as "unprocessed". So my question is ...
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2answers
623 views

Cleaning LiDAR points that classification algorithm misses?

There are numerous methods for classifying ground and not-ground points from raw LAS point clouds. They all do a great job, depending on local circumstances, but inevitably even when algorithm and ...
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2answers
2k views

Converting TIFF file to LAS file in QGIS?

I've been asked by a client to compile LiDAR files (currently in GeoTiff format) into a LAS dataset. Is this possible within QGIS? I have downloaded LAStools, but I'm still fairly new to LiDAR so ...
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1answer
480 views

Converting coordinates from GCS_WGS_84 Linear_Meter to lat/long?

I have a LiDAR .laz file with points from Toulouse (France). I convert this file to a .las file using LAStools's las2las function. Then, using lasinfo on this .las file gives me some information, ...
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1answer
345 views

Which type of point cloud is more accurate: from airborne LiDAR or aerial photos?

I have been offered two types of point cloud for my 3D Project. The data will be used by the environmental agency in various projects e.g. flood-risk analysis, dyke conservation, and nature ...
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1answer
4k views

Converting LiDAR point cloud to 3D mesh?

I have an unstructured point cloud of a street in LAS format (.las), scanned from a driving car. The point cloud also stores RGB information. Is there any software that can convert the point cloud to ...
5
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2answers
294 views

Using iterator for lasd files in ArcGIS ModelBuilder?

I am trying to use model builder to create a number of DEMs from LiDAR point clouds. To do so, I need to filter the point clouds for ground points only and then convert the points to raster. In the ...
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0answers
471 views

r.in.lidar Error: 'Raster map not found' in QGIS 2.18.14 GRASS [closed]

First of all I would like to say, that I have checked all the open threads (with almost the same title) about r.in.lidar errors and in general GRASS and it's "raster map not found" errors within QGIS ...
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2answers
349 views

LAStools menu seems to be incomplete in QGIS?

I am using QGIS 2.18.2 Las Palmas on a MacBook Pro running OSX 10.13.1 High Sierra. I followed Martin Isenburg's instructions how to install LAStools toolbox in QGIS and the LAStools menu is available ...
2
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1answer
1k views

Importing LiDAR (.las) data in PostgreSQL with PDAL?

I am following this tutorial to load LiDAR data into PostGIS/PostgreSQL database. The order is: Create extensions: CREATE EXTENSION postgis; CREATE EXTENSION pointcloud; CREATE EXTENSION ...
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1answer
1k views

How to install PDAL in Windows?

I want to import .las files to PostGIS. As I found out I can do it by using PDAL. However, I cannot find the right way to install it in Windows. I downloaded a folder from here https://www.pdal.io/...
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1answer
175 views

Batch processing multiple files with MCC-LIDAR?

I want to classify ground points from multiple LiDAR tiles (.las files) using MCC-LIDAR software. I already made some research and I have found this sourceforge thread; however, it is not that clear (...
2
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1answer
357 views

Reading LiDAR attributes from a .mat file?

I am working on some LiDAR dataset. I am used to importing the LiDAR data from .las files. I generally use liblas library in Python to import the same. Recently, I found the dataset in .mat format ...
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1answer
385 views

Seeking LiDAR data processing and analysing tool? [duplicate]

I am working on Lidar VLP-16. Can you advise me about the open source software that I could use for processing the lidar data and extract the object from the data?
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1answer
810 views

Converting LiDAR ellipsoidal heights to orthometric heights?

Is there any tool to convert all Z attributes (ellipsoid h) value into orthometric height (H)? The idea is, having a point cloud (.las) and geoid undulation EGM08 (.asc) get a point cloud (.las) with ...
2
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1answer
222 views

Importing point cloud data to Terrascan is incorrectly gridding it?

I am using Terrascan to strip vegetation of some ASCII files to create a bare earth model and also to convert the ASCII txt file into a *las (1.2) file. However, I have noticed that Terrascan (at ...
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1answer
490 views

Generating Canopy Height Model (CHM) with Quick Terrain Modeler?

I currently looking forward to process LiDAR point clouds (forest data) using Quick Terrain Modeler (QTM), but is it possible to create Canopy Height Model directly using the software?
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1answer
192 views

Stamping two rasters in QGIS?

I have two LiDAR datasets; one of 1m resolution and another of 2m resolution. I want to stamp 1m LiDAR data on 2m LiDAR. Similar tool is available in Vertical Mapper in MapInfo called as Splicer ...
4
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3answers
842 views

Extract linear features (roads) from DEM

I have a 1x1meter DEM and the original LiDAR point cloud. I need to create a vector feature with roads. Are there any tools in ArcGIS to do this? Or any ideas for the algorithms to try to do this in R ...
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0answers
54 views

How to diagnose an “invalid data” error message using the r.sun GRASS tool?

I'm using the r.sun GRASS tool to map solar inputs and shade or lack of it in Pacific NW salmon streams. I clipped out the input raster data (a canopy height model, aspect, slope) for a 15 hectares ...
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1answer
1k views

Classifying LiDAR ground points using laspy?

I have a classified LiDAR point cloud (.las) with misclassifications. The walls of steep surfaces that should be ground (class 2) have been misclassified as vegetation (classes 3, 4, 5). I am ...
3
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2answers
499 views

Finding tree canopy width using PDAL?

I want to classify (and separate) houses from trees (high vegetation) in point cloud data using PDAL. I use height filter for this purpose. Our high Vegetation lies in the range between 5 and 10 ...
2
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0answers
33 views

Delineating adverse/favourable areas adjacent to roads using ArcGIS Desktop? [duplicate]

I have a client in the forestry sector that would like me to run some maps with criteria that I’ve never managed for. These maps will delineate (using polygons) areas of slope (0-20%,20-40%,>40%), ...
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2answers
185 views

Lidar data for Israel [closed]

Are there any public sources for LIDAR data for the country of Israel? Searching online has not lead me to find any sources out there.
4
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1answer
141 views

Faster way to find nearest neighbors with LASlib?

I'm using LASlib to find the nearest neighbors of a subset of points in a point cloud. I'm using brute force to find nearest neighbors, which is extremely slow (my code below). Is there a better way,...
2
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1answer
169 views

Creating filter stage of type filters.height using PDAL?

I use PDAL to find the height of points from LiDAR data. When I run the command: pdal translate myfile.las height.bpf height --writers.bpf.output_dims="X,Y,Z,Height;" It throws me the following ...
2
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1answer
180 views

Unexpected argument grid_dist_x using PDAL

I'm trying to convert a .las file to a DTM/DEM using PDAL, but having the issue of multiple bands instead of one. I went through Generating a DTM and writers.gdal but it prompts an error message: ...
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0answers
36 views

Production of DEM on ArcMap from LiDAR data? [duplicate]

I am trying to produce a DEM for my dissertation (i'm relatively new to ArcGIS) so that I can conduct hydrological analyses of catchments. I have downloaded LIDAR (.laz 2x2 km) data and have created a ...
0
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1answer
205 views

Converting point cloud (.txt) to shapefile with ArcPy? [duplicate]

I have lots of .txt files (point cloud) which are raw data acquired from from LIDAR and containing XYZI values. I want to convert them to shapefile. Is there a way I can do that instead of adding XY ...
4
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2answers
866 views

How to write the results of lidR grid_metrics to a georeferenced raster?

I'm using the lidR package to calculate LiDAR grid metrics (p.18 documentation) for forestry applications. For example, the following calculates the mean elevation within a 20m cell: library(lidR) ...
2
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1answer
668 views

3D to 2D from point cloud using a georeferenced orthophoto? [closed]

I have 3D point cloud (laser scanning) and an orthophoto, geo-referenced by a TIFF World File (.tfw). I want to project every 3D point of the point cloud into the 2D image. Here is an example of a ....
4
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1answer
100 views

Erratic results from filters.normal in PDAL?

Given this roof structure: I get the following output for the normalx, after using: { "type":"filters.normal", "knn":8 }, (orange to purple : -1 to 1) Comparable situation for ...
2
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2answers
3k views

Converting .las to .pcd file using PDAL?

Is it possible to translate .las files to .pcd with PDAL? If so, using which tool? I need an example about how to set the command-line with such tool. If it is not possible (or alternatively), is ...
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1answer
493 views

Classifying LiDAR data to mid vegetation using LAStools?

I want to classify LiDAR vegetation points in low and mid vegetation, using LAStools. High vegetation is simple to get, using top of canopy (first return), but how about low vegetation, and mid? ...
2
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0answers
408 views

LAStools errors in QGIS: 'cannot open lasreaderlas with file name .las', 'could not open lasreader'? [closed]

I am experiencing some problems with LAStools. I have two QGIS separate installations: 2.14.17 is a standalone installation and 2.18.11 is a Osgeo4w installation. I have followed the procedure to ...
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1answer
256 views

PDAL Reader.las and Writer.las warning: 'found invalid value of '0' for point's return number'

I am trying to read and write LAS (*.las) file using PDAL but getting the following warning messages by PDAL's LAS reader and writer for ASPRS LAS files. (pdal pipeline readers.las Warning) C:/...
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1answer
555 views

Seeking open source alternative of Las Tools [duplicate]

I am finding any open source alternative of Las tools , i Google but i found las Utitly which is also not the Open source alternative But i want open source alternative of Las Tools,
2
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1answer
155 views

Heat mapping forestry height trends using ArcGIS?

I am using ArcGIS and have access to Spatial and 3D Analyst extensions. I've attached a link to a picture of a 1m raster “canopy height model” which was derived from LiDAR and displays tree heights (...
2
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1answer
151 views

Converting .las files to LAS datasets using ModelBuilder iterator?

I have 1500 individual LAS files and I need to move them to separate LAS datasets (so 1500 LAS datasets). I've used iterator (iterate files) in ModelBuilder and it creates 1500 individual LAS ...
4
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1answer
631 views

Converting LAS data from buildings to detailed shapes using ArcGIS Pro?

What we want to achieve is to convert LAS data to a GIS format like shapes. On the internet, there are enough examples how to convert the LAS data height to a building footprint. What we want is ...