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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2
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2answers
82 views

Correcting merged LiDAR DEM with outliers in inner edges?

I've created a DEM from LiDAR data. After combining all the files, I could see that there are some problems through the tile borders. This is an screen focused in one of the cross section of 4 files ...
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2answers
174 views

Why such a large difference between overlapping LiDAR DEM values?

Background: Using Arc Desktop 10.5.1, I have been tasked with mosaicking two adjacent LiDAR rasters (I'll call them A and B). They were flown, processed and supplied under contract by different ...
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0answers
175 views

Create laspy file object without creating a new file

I would like to create a new laspy.file.File object in memory without having to create a reference .las file. The basic procedure is read sample.las clip sample.las by converting the x and y ...
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1answer
265 views

Preventing interpolation outside of data extent with LAS Dataset To Raster ArcMap?

When I use the LAS Dataset To Raster tool in ArcMap I get an unwanted interpolation outside of the actual study area, like this: According to Esri this can be prevented by changing the definition of ...
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1answer
256 views

Fixing spikes in DSM from LiDAR?

I have a DSM derived from drone LiDAR that I want to use as a base to drape imagery and, paired with a DTM, as a basis for estimating canopy height/volume. Unfortunately, the DSM has has many "spikes"...
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1answer
530 views

Visualizing LAS with matplotlib

I'm trying to create a 3D scatterplot using an las file that contains xyz and return values. I want to keep all returns but would like to subset the cloud. I've learned how to subset using laspy so no ...
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1answer
442 views

Displaying LiDAR data with too many points in ArcMap?

I have imported LiDAR data into ArcMap in the shape of a Las DataSet with twelve .las files (contains over 100 million data points). I believe the file itself is working properly. However, no points ...
5
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1answer
612 views

GRASS's r.in.lidar error in QGIS 3: “North must be north of South”

I have LAZ files that I unpacked with laszip.exe, then I ended up with LAS files. These files showed no error when making a LAS dataset in ArcGIS. I used this dataset several times without ant issues....
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1answer
313 views

Locating outliers in LAS Dataset with ArcGIS?

According to the statistics and symbology of my LASD I have outliers. See below: How can I locate them in ArcGIS 10.x and do further analysis with them? I cannot query the dataset or select point? So ...
4
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1answer
180 views

Setting GroundFilter parameters for low density point clouds?

I'd like to use the function GroundFilter on my dataset. However, the manual says that the default values of the parameters used by this function (g parameter, w parameter) are related to a high ...
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0answers
220 views

Visualizing LiDAR data in a detailed footprint of rooftops with ArcGIS [closed]

For the last couple of weeks, I have been doing a research for making a detailed footprint with LiDAR data. The detailed footprint is needed for visualizing a 3D model. With a detailed footprint I ...
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2answers
7k views

Installing LAStools in QGIS 3.0?

I don't know how to install LAStools in QGIS 3.0. In QGIS 2.18, you can incorporate it as a provider in Processing -> Options-> Tools for LiDAR data (for example: Installing LAStools in QGIS 2.4?). ...
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1answer
348 views

Cropping raster and merge it to overlapping DEM?

I am working with an existing DEM of a river and its surrounding area in QGIS (actually a virtual raster from four separate DEM TIF tiles). My goal is to add a bridge's profile to the DEM. I have a ...
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0answers
102 views

Rice Field Levee Contours - .2 foot interval needed - LiDAR data? [closed]

I am a rice farmer in Arkansas and would like to create levees along contour lines in a field at a .2 foot interval. How could I utilize LiDAR data to map 0.2 foot contour intervals across my area of ...
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0answers
189 views

FUSION's PolyClipData creates corrupt LAS file?

I am trying to learn LASPY and am following a tutorial. I got an error when starting up using: import laspy infile = laspy.file.File("./laspytest/data/simple.las", mode="r") where I got a storage ...
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2answers
2k views

laspy ValueError: buffer size must be a multiple of element size

I am trying to learn LASPY and am running into road blocks off the bat. I first ran into and Error 8 (Not enough storage is available to process this command) using my full sized LAS file (1.7GB). I ...
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1answer
124 views

Which QGIS installation for Windows comes with r.in.lidar?

I am running QGIS 2.18.14 (QGIS code revision: ff83b9a479) on a windows 7 machine, it comes with GRASS 7.2.2 (Code Revision r71496), but it does not come with r.in.lidar. I have noticed QGIS 2.18.16.1 ...
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1answer
43 views

How does MERIS collect vegetation height data?

In GlobCover 2005 and 2009 project, the sensor used for spectral data collection was MEdium Resolution Imaging Spectrometer (MERIS). It observes the Earth in 15 spectral bands in visible and near ...
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8answers
6k views

Editing LiDAR point cloud to remove noise/outliers present below and above ground?

I have "dirty" LiDAR data containing first and last returns and also inevitably errors under and over the surface level. (screenshot) I have SAGA, QGIS, ESRI and FME at hand, but no real method. What ...
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3answers
536 views

How to filter point cloud by flightline in R?

The lidR package in R provides a way to mark individual points in a point cloud with a flightline ID by using lasflightline(). From the documentation: Retrieve each individual flightline by ...
2
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1answer
148 views

How to incorporate stdmetrics in gridmetrics function?

I am attempting to feed the lidR gridmetrics function a list of metrics. I can generate the list of metrics within a function (following this example): myMetrics = function(z, i) { metrics = list( ...
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1answer
185 views

Classify LAS By Height tool is not yielding any results?

The classify LAS by height tool (CLHT) in ArcGIS says that it will only reclassify LAS points with class codes of 0 or 1 (http://pro.arcgis.com/en/pro-app/tool-reference/3d-analyst/classify-las-by-...
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2answers
125 views

Getting statistics in cross sections at varying heights in LAS files?

I am looking to cross section my forest at varying heights. I have high return LAS data (8 points/m2 and average point spacing of 0.2m) and I am looking to do more than the simple 1, 2, 3 approach of ...
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0answers
103 views

Completing Coordinate transformation?

I have two airborne lidar datasets and, for purposes of comparing change between the two, would like to standardize the vertical and horizontal coordinate information for each. The plan is to ...
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1answer
698 views

error: Compression support not enabled in liblas configuration

I am using liblas 1.8.1 and laszip 3.1.1 on Mac OS High Sierra. Both were installed using brew install <package>. I am looking to get information from a laz file using the following command: ...
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3answers
916 views

Open source approach to classifying and removing LiDAR points from overlapping scans?

The attached screenshot shows a LiDAR point cloud with significant overlapping scans. This point cloud tile is part of the MN statewide LiDAR dataset which has 25% scan overlap and 1.5 NPS. For many ...
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1answer
495 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
59 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 ...
6
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1answer
626 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
153 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
351 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
725 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
143 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
35 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
112 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 ...
2
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1answer
2k 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. ...
0
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1answer
133 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 ...
5
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2answers
827 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
588 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
361 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 ...
3
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1answer
6k 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
416 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
562 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 ...
2
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2answers
419 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
2k 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 ...
10
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1answer
2k 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/...
1
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1answer
212 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
404 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 ...
0
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1answer
406 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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