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.

Filter by
Sorted by
Tagged with
1
vote
1answer
182 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-...
2
votes
1answer
177 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.
1
vote
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, ...
5
votes
2answers
5k 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
648 views

Adding height from nearest XYZ point to geom table in PostGIS?

I have been trying to get this query right and just can't seem to. I have a building polygon table with over 7 million polygons, indexed. I then have a gridded height XYZ table with attribute 'height'...
6
votes
1answer
169 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-...
1
vote
1answer
172 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 ...
10
votes
8answers
4k 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 ...
0
votes
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 ...
2
votes
1answer
752 views

How to import raster (.asc) data to PostGIS?

I am using Postgres 10.3 / Postgis 2.4.2, and I have thousands of ".asc" files (LiDAR DTM/DSM files) to import to the db. However, the format is something like: ncols 1000 nrows 1000 xllcorner ...
1
vote
2answers
330 views

Identifying SBET coordinate system and reprojecting it with PDAL?

I've received discrete return LiDAR data from a data provider, which was acquired with an Optech C-300 scanner. In addition to the LAS data, the delivery includes the trajectory information in the ...
7
votes
5answers
15k views

Converting LiDAR data to raster (DEM/DSM) for ArcGIS input?

I was wondering if there is an option to convert LiDAR data (.las) to a raster/grid (DEM/DSM) format that ArcGIS 10.0 can read?
4
votes
1answer
260 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 ...
3
votes
1answer
194 views

Extracting only elevation data from NASA's GLAS Satellite LiDAR to create raster DEM?

I'm trying to open data downloaded from NASA's Earthdata site in ArcGIS 10.4.1. Specifically I'm trying to open "GLAS/ICESat L2 Global Land Surface Altimetry Data (HDF5) V034" (Image below, ...
10
votes
7answers
8k 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
1answer
513 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. ...
6
votes
1answer
2k views

Reprojecting LiDAR data with libLAS, error: “latitude or longitude exceeded limits”?

I have a lidar file (file.las) with the following spatial reference: Spatial Reference: PROJCS["NAD83 / UTM zone 11N", GEOGCS["NAD83", DATUM["North_American_Datum_1983", ...
1
vote
0answers
60 views

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....
2
votes
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 ...
0
votes
1answer
504 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 ...
4
votes
1answer
221 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 ...
2
votes
1answer
119 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 ...
2
votes
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 ...
1
vote
1answer
124 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 ...
2
votes
2answers
170 views

Integer vs Non-Integer LiDAR

A LiDAR user is telling me that his LiDAR data acquired from my organization has only integer LiDAR in certain areas. He is requesting non-integer LiDAR for those areas. First, can anyone help explain ...
2
votes
1answer
567 views

How to write multiple .las files from polygon clipping with PDAL?

I am using PDAL (through Python) to crop multiple polygons from a point cloud and store them as separate files. For efficiency reasons I would like to define this in a single pipeline. However, using ...
1
vote
2answers
329 views

Merging LiDAR tiles without losing data in QGIS?

I'm trying to merge some LiDAR tiles together but when I do, the clarity of the image drops, so I think that means I am losing some data. How do I merge the tiles and keep all of the data and the ...
1
vote
0answers
54 views

Fill gaps in dem created from .laz file [duplicate]

I've been trying to fill those lidar scan lines in my dem with no avail. Is there any way to interpolate those "gaps" to get a clean dem? I used las2dem to create the dem from .laz file
7
votes
2answers
187 views

Prevent SAGA in QGIS 3.0 from creating certain outputs?

I'm wondering if there is a way to prevent SAGA from generating temporary files. For example, if I just want to generate a slope map using SAGA I have to wait for all 11 other grids to get processed. ...
2
votes
2answers
138 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 ...
4
votes
1answer
188 views

Importing multiple .asc files into PostGIS violates check constraint. Why?

I am importing thousands of .asc files into PostGIS into this table: CREATE TABLE stg.COUNTRY_1M(rid serial primary key, rast raster); CREATE INDEX ON stg.COUNTRY_1M USING gist (st_convexhull(rast)); ...
3
votes
2answers
535 views

Clipping object of class LAS with polygon shapefile using lidR?

I want to make a simple clip with my .las 3D-Pointcloud. Therefor I use the lasclip() function. Import .las: lidar <- readLAS("~/data.las") lidar gives me class : LAS (LASF v1.2) memory ...
2
votes
2answers
227 views

GRASS r.in.lidar (las to raster) inside Python loop?

I have a loop in Python to list out LAS files in a folder, and run two commands in Grass GIS on these files to write them out as rasters. The loop runs but at the end I get an arg must be string not ...
5
votes
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 ...
2
votes
1answer
543 views

Converting DEM to LAS file? [duplicate]

Is there a way to convert a DEM raster to a .las file using open source software and/or any tools that come along with a complete ESRI license? I have been able to achieve this using the LAS Toolset ...
2
votes
3answers
526 views

Creating DEM from multiple .las files using LAStools in ArcMap?

I am attempting to create a DEM for a raster large dataset, with over 500 .las files. Within the las2dem tool, within the LAStools toolbox there is not an option to select an entire folder, nor can ...
4
votes
3answers
633 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 ...
5
votes
2answers
902 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 ...
12
votes
4answers
5k views

Comparing two Digital Elevation Models (DEMs) from LAS files?

I have two LiDAR files (.las), one is original let's say with X points. And the other is copy of the first .las file but with Y points, where Y is less than X. Now, I want to compare the Digital ...
2
votes
2answers
67 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 ...
1
vote
1answer
121 views

Batch processing LiDAR files (.las to raster) with PyQGIS?

for layers in glob.glob("*.las"): processing.runalg("grass7:r.in.lidar", "input_las",5,1,"",1,100,"","",5,"","",False,True,True,"331289.57265,337990.42735,4558790.0,4560890.0",0,layers+"E:/...
0
votes
1answer
111 views

Batch scripting r.in.lidar in pyQGIS for LiDAR DEM output? [duplicate]

I need to use pyQGIS to write a script that will run the r.in.lidar GRASS 7 on a set of LAS files. I am terrible at Python, but I need this for my task. I would like to process as a batch. How can I ...
5
votes
1answer
375 views

Georeferencing terrestrial LiDAR point cloud?

Recently I took a Faro Focus terrestrial laser scanner to a forested area and collected multiple scans for 12 fixed radius plots. Each plot had 5 GPS points collected within it in hopes to ...
4
votes
1answer
755 views

Improving accuracy of georeferenced LiDAR data?

Often I obtain LiDAR data for concept studies and conventional survey (in .dxf format) over a small portion of this. The LiDAR typically covers the broader area and is used for broader studies, ...
6
votes
1answer
2k views

numpy array to GTiff using rasterio without source raster

I have a numpy array that represents rasterized data from a LiDAR point cloud. For example: import numpy as np import rasterio arr = np.random.randint(5, size = (100, 100)) I know information about ...
1
vote
1answer
120 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 ...
0
votes
1answer
57 views

access r.in.lidar through pyGIS console [duplicate]

How can I access the r.in.lidar algo with the pyqgis console? i tried to import processing and algolist but r.in.liad under the GRASS GIS algo does not get listed. Also Checked the options iunder ...
5
votes
1answer
382 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....
14
votes
4answers
2k views

Performing dikes extraction from DEM?

I do have DEM of 1x1 meter and original LiDAR point cloud in .las, that DEM is made of. I need to extract river dikes (highest points of the dikes) to vector feature (point, polyline). Any idea for ...
2
votes
4answers
2k views

Identifying individual trees and segmenting crowns from LiDAR CHM data?

I have a classified LiDAR 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). ...