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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63 views

Estimating building and vegetation volume with unclassified LiDAR datasets?

I'm trying to determine the ratio of building to vegetation change (i.e. how has the volume of built structures changed in proportion to the volume of vegetation) in a city over a period of five years....
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1answer
82 views

Interpreting cell coordinates from DEM?

I'm using Environment Agency DTM LiDAR data which I import into Mathematica in ASCII format to produce ground surface models, sections, etc. The process works fine, but I'm unclear whether the cell ...
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1answer
1k views

Accessing raw data from LAZ file in Python with Open Source software?

Is there anyway to access raw "LAZ" (not LAS) datasets in Python? I was trying to with ArcPy (I'd prefer not too), but it doesn't seem able to access LAZ. I'd prefer to work with the raw LAZ file and ...
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1answer
251 views

Splitting LAS file into smaller LAS files by shapefile geometry boundaries - using PDAL or Global Mapper. [duplicate]

I've looked up pdal documentation on how to clip LAS point cloud files:- https://pdal.io/workshop/exercises/analysis/clipping/clipping.html Referencing this example, and having a quick look around, ...
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1answer
247 views

Error in reading point cloud data (.las) in R?

I want to generate a DEM using a point cloud (.las) for which I tried reading it in R using rlas, lidR and rLiDAR : readLAS command and none of it seems to work. The LASfile is not being read at all....
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0answers
65 views

Parallel optimization for query over LiDAR dataset

I'm using PostGIS + pointcloud to store a huge dataset of LiDAR point (2M patches of 600points) I query this database to obtain the altimetic profile between two points. At the moment I have a huge ...
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1answer
477 views

Why ground model from point cloud in Global Mapper is inaccurate?

I have a LAS file that I assumed was based on LiDAR, but it is actually based on ADS (airborne digital sensor) imagery, according to the body that captured the data. I load the file in to Global ...
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1answer
81 views

LIDAR scans of the same location give very different values [closed]

In QGIS, I have a number of LIDAR scans of the same geographic location over a number of years. The actual values in the .asc files differ markedly (see image). Do the different value ranges for the ...
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1answer
231 views

LAS/LAZ parser for NodeJS

I cannot find any popular libraries for parsing (reading into memory) of LAS or LAZ (lidar data) files in NodeJS (desktop Javascript) https://github.com/yuyou/liblas4node/blob/master/lib/liblas.js ...
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1answer
102 views

Combing multiple LAS files with different vertical and horizontal accuracy?

The data set in question was made using .las and .zlas files from respectable sources. Data set 1 was collected in the Fall of 2014. The RAW flight line swath data was processed to create classified ...
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3answers
151 views

Maximum number of returns per laser pulse in airborne LiDAR?

What is the maximum amount of returns a discrete aerial laser scanner is capable of recording? For example in a LAS 1.2 metadata under Point Data Records there is the category 'Number of Returns' ...
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1answer
87 views

Constructing a function to pass to lidR::grid_metrics

I am attempting to write an R function, as part of a package, that takes a lidar tile (LAS object) and a vector of cut-points defining vertical layers, and returns a RasterStack where each layer has a ...
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0answers
56 views

LiDAR first and lastreturns eCognition [closed]

Recently I downloaded the new version of eCognition Developer. I remember that before when processing LiDAR data by using algorithms it is pretty easy to generate LiDAR first and last returns. ...
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1answer
405 views

Unable to install FUSION in QGIS 3.2?

I'm unable to install FUSION in QGIS 3.2 on Ubuntu 16.04. Andre Silva on Creating DEM from LAS file without using LAStools? says to use the same procedure as LAStools (up to QGIS 2.18 version). I've ...
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1answer
92 views

Extracting Road Terrain Properties using DEM / LIDAR

I want to extract following road terrain data from DEM but I'm not sure if its possible. Can i extract these attributes using LIDAR if not DEM ? These are the data fields I need: Horizontal curve ...
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1answer
60 views

PDAL info with docker yields no output?

I am using pdal info within a docker env for a specific .las file (~2 GB). docker run -v /Users/user.name/workspaces/testData:/data pdal/pdal pdal info /data/sp.las --developer-debug Unfortunately, ...
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1answer
94 views

Optimizing workflow for FUSION's PolyClipData?

I have multiple large LiDAR datasets (.laz) from different areas, where I need to extract buildings. I have prepared a shapefile containing a buffer around the buildings I care about, and are using ...
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1answer
57 views

Whitebox Tools ClipLidarToPolygon writes no points to output file?

Running Whitebox Tools (v 0.11) on Windows from the official binary. The ClipLidarToPolygon tool creates an output LAS file with no points and the message There are fewer than two points in the LAS ...
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1answer
902 views

Merging multiple LiDAR (.las) files?

I downloaded about 9 LiDAR scenes from USGS and I want to use ArcGIS to merge them so that I can carry out tasks on them together as opposed to one by one.
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2answers
362 views

Adding RGB values to Laspy synthetic point generation?

What is the correct way to add RGB values to points made from scratch? Laspy is working great for me so far. I want to add RGB values to synthetic points that I've generated. I am using 2 numpy ...
3
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1answer
295 views

Digitize objects in a LiDAR point cloud?

I am working with LiDAR point cloud data of road networks. The goal is to digitize all visible objects like hydrants, streets, sidewalks. My input data is available in LAS or ASCII format. My first ...
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2answers
165 views

Saving LAZ files to different location from input (LAS) files? [duplicate]

All of the command line examples I'm seeing show how to create LAZ files in the same folder as the LAS files, e.g.: C:\Folder\tools>laszip F:\Folder\LAS_points\*.las Unfortunately, I don't have ...
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1answer
310 views

Importing LiDAR point cloud classes in Potree?

I can't find a way to import classes (roof, vegetation, ground, etc..) in Potree. I generated the web page, except I get the black point cloud. When I, for example, open .las file in ERDAS Imagine, I ...
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2answers
462 views

Why did Esri create .zlas compressed LiDAR files instead of adopting .laz?

I am talking about the Esri Optimized LAS file format for compressed LiDAR files (.zlas). While the uncompressed format (.las) from ASPRS was adopted by practically the entire Remote Sensing and GIS ...
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2answers
104 views

Strange Pattern in LIDAR derived DSM raster

I produced a DSM raster from LIDAR data for eastern Kentucky. There are strange lines from southwest to northeast. Do you have any idea what those might be? I generated the DSM raster with both first ...
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1answer
252 views

LiDAR returns over water bodies?

I have obtained LiDAR data from my environmental agency in order to obtain the relative heights of each watercourse station. A far as I know, LiDAR signals do not get returned over water bodies. ...
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1answer
231 views

Choosing LiDAR tiles with vector data using LAStools?

So the problem is that I have a huge amount of LiDAR tiles (in .laz format), but need only part of them that are within the borders of the city. When I load all the tiles to LASTools, I have ...
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1answer
300 views

Converting .pcd LiDAR binary compressed file to .las format?

I have LiDAR data in the format of .pcd in a binary compressed file (version .7). How can I convert it into .las format or any other that can be readable by LAStools in ArcGIS 9.3 version ownwards? ...
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2answers
261 views

Reprojecting LiDAR data with libLAS error: “x scale and offset combination is insufficient to represent the data”

Disclaimer: This is a duplicate of this, a question without an answer. This is not, however, a duplicate of this, as it is a different error. I have a LAS file projected in EPSG:32636, and I need to ...
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2answers
395 views

Failed to install Potree on Ubuntu 18.04 Bionic

I am trying to install Potree on my computer and I am stuck. I am following these instructions: $ sudo apt-get install python-software-properties git $ sudo apt-get install build-essential cmake g++ $...
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1answer
67 views

PDAL pipeline could not connect to server: Connection refused

I am trying to import .las files to the postgres database. My pipeline is: { "pipeline":[ { "type":"readers.las", "filename":"data/pt000002.las", "spatialreference":"EPSG:4326" }, { "type":"...
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2answers
211 views

How to run PDAL pipeline with docker

I used to use PDAL with conda environment, and in that time I used pipeline command with the simple: sudo pdal pipeline -i /Documents/laz2pg.txt And that did the work. But, now, at the moment, I ...
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2answers
74 views

Availability of Frequent LiDAR Data in UK?

I am looking for LIDAR data of grasslands located all around UK with a spatial resolution of 1m and a frequency of at least once a week. I've already had a look at the Environmental Agency but their ...
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1answer
118 views

PDAL works in Windows command but not in OSGeo4WShell?

I want to import a pointcloud into a PostGIS database. AFAIK you accomplish this with PDAL which comes with OSGeo4W. I was following this tutorial: OSGeo4W LiDAR tutorial and also this tutorial PDAL....
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1answer
442 views

Getting buildings multipatch from LiDAR data without building footprints?

I have a 3D LiDAR data and aerial images. Is there a way to obtain the buildings multipatch (.shp), given that I don't actually have the buildings' footprints?
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2answers
566 views

Installing PgPointCloud extension for PostgreSQL on Ubuntu Bionic

I'm stuck with the installation of the PgPointCloud extension for PostgreSQL. I found this article: https://connect.boundlessgeo.com/docs/suite/4.6/dataadmin/pointcloud/install.html But when I run ...
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1answer
103 views

Loading LIDAR data to POSTGRES and use it with DJANGO [closed]

I have some project at the Faculty and I don't know from where to begin. I have point cloud data (LIDAR data) and I need to make the website with that data on it and with functions for some sort of ...
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1answer
121 views

PDAL error: “Couldn't create filter stage of type 'filters.cpd'”

I would like to use the cpd filter to transform a point cloud, but I am heading to the following error: RuntimeError: Couldn't create filter stage of type 'filters.cpd' which comes from the ...
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1answer
166 views

Naming conventions for LiDAR files?

I can't figure out what is specifically being referenced by the names of these .las files: They correspond to a specific quadrangle, but can't figure out quite how.
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1answer
166 views

JSON pipeline in Python doesn't create any output file?

I have ground LiDAR point cloud with some noise points. I would like to use filter.statistics in PDAL (in Python 3.6) using JSON pipeline to filter the noise out. json = """ { "pipeline":[ "/9A-...
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1answer
161 views

Visualizing extra bytes from LAS 1.4 in Potree?

I was wondering if it is possible to visualize the information that can be stored in the extra bytes of the LAS 1.4 file. This could be really helpful for validating features that have been calculate ...
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1answer
117 views

Masking LiDAR points to create DEM in ArcGIS Pro with ArcPy?

I have an irregular LiDAR point cloud dataset, so when I try to create a DEM or DSM, the points are connected across the irregular edges of the LiDAR point cloud. I thought that creating a mask ...
4
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1answer
245 views

Selecting LiDAR return point type in LiDAR dataset with ArcPy?

I am trying to create a Digital Earth Model (DEM) using ArcPy under ArcGIS Pro 2, but I am running into some problems. I can generate a DEM within ArcGIS Pro by selecting only the ground points ...
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1answer
443 views

Creating 3D polygon roof from LiDAR data using FME?

I have LiDAR data of a building and would like to construct a 3D Model using FME 2016. The LiDAR data shows that the structure has sloped roofs with various other elements on the roof surface (e.g. ...
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0answers
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Error reprojecting point cloud with liblas 1.8: “latitude or longitude exceeded limits”? [duplicate]

I was previously reprojecting a point cloud in .las format using liblas 1.7.0 (with GeoTIFF 1.4.0 GDAL 1.10.1) as follows: las2las /tmp/input.las --a_srs EPSG:4326 --t_srs EPSG:3857 --scale 0.001 0....
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1answer
202 views

Is the ground level cross section of a normalised lidar dataset flat? [duplicate]

If I normalise a lidar dataset I am (according to my thinking) simply subtracting the first return heights from the ground heights. Thus the resulting dataset will only contains the height above ...
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1answer
446 views

Normalizing a digital surface model? [closed]

I am trying to generate a normalized DSM by subtracting the original DSM (oDSM) from the DTM. To generate the DTM I had to first use a median filter on the oDSM (remove noise) and then use a ...
2
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1answer
105 views

Elevation contours from .JP2 / .J2W files?

Is there a way in ArcGIS, Global Mapper, or CAD to generate elevation contours or any sort of surface data from a .JP2 file? I've never been provided this format before and our client is telling us ...
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1answer
113 views

How much do leaves on/off affect the number of LiDAR ground returns?

We would like to collect a generic purpose topographic LiDAR dataset over a large region in Belgium. Our minimum requirement is to achieve at least 1 point/m² on the ground. Ideally, we would like to ...
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1answer
164 views

Lidar DEM produces odd results related to topographic aspect

Background: ArcGIS Desktop 10.5.1, Spatial analyst We have acquired two bare-earth DEMs derived from lidar. YEAR2007 was produced in 2007, and YEAR2015 eight years later. Both are 32-bit, floating-...