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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612 views

Reading SBET file in python?

I have an SBET (Smoothed Best Estimate of Trajectory) file that I would like to read in python. I found these links that discuss options for reading/writing SBET files, but I was wondering if our ...
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0answers
141 views

Problem reprojecting LiDAR data using liblas

I have multiple lidar data sets and I am trying to reproject them using liblas. They are missing the coordinate system in the header information so I assign them an SRS using las2las --a_srs: las2las ...
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3answers
675 views

Filtering out canopies and buildings from DSM to have a bare earth elevation

Can anyone suggest methods in filtering out trees and buildings from a DSM so as to come up with a reliable DEM? What I have is a grid from a LIDAR data (.tif file, with 1m resolution). I was going ...
6
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2answers
788 views

How to de-noise a DSM

I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
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1answer
615 views

How to visualize a point cloud in 3D with GRASS?

I'm new with qgis and grass so I'm sorry if there is a straightforward answer for this question but I can't seem to get it done. I've imported a pointcloud into qgis from a datafile. Now i'd like to ...
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1answer
96 views

libLAS georeference las file and update header

I am just starting to use libLAS and I had a small issue. I have next code to generate a las file with georeferenced points: std::ofstream ofs; liblas::Header header; liblas::SpatialReference srs; ...
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1answer
69 views

How exactly does a single laser pulse from LiDAR act? [duplicate]

I'm trying to understand the behavior of a single laser pulse in a traditional airborne lidar. I understand that the multiple return values are representative of the surface that reflected the ...
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1answer
150 views

Creating building footprints from LAS files

I wish to create building footprints from the classification in our LAS files. I have filtered out the building points, using the point cloud filter. But I now trying to join the outermost points of ...
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1answer
101 views

How to exclude water during contour generation?

I recently acquired a LiDAR data set that included a 1 meter DEM. I generated 1, 2 and 5m contour layers but I am seeing a lot of contours within water bodies. I suspect this is either caused by wave ...
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1answer
213 views

Calculating coverage of vector polygon over other polygons?

I have a shapefile file that contains a LiDAR footprint and I'm trying to figure out how much a county is covered by the LiDAR footprint. Two separate shapefiles. The attribute table for the county ...
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1answer
111 views

Obtaining sink morphometry from local minima points

I am working on LiDAR data from GIS and R and I want to extract landforms from the DEM. I have found a method to obtain local minima points of my LiDAR data. However, I would like to obtain the ...
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0answers
160 views

Orthogonal correction of building footprints after extracted from a raster

I have ArcGIS 10.1 and am working on a project involving extraction of vegetation and building classes from LIDAR (unclassified) data and aerial imagery (resolution 30x30cm). I have managed to ...
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2answers
177 views

LiDAR intensity image from multiple flight lines?

I'm working with multiple raw las tiles, and I've used Fusion to create an intensity image, but it shows the flight line overlap (see below). Any idea how can I smooth the image so that the overlap is ...
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2answers
2k views

Tool for exporting las data

Is there any tool available for extracting the X, Y and Z channels from a .las file and exporting them to a .csv or similar file?
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2answers
1k views

Converting a .lasd (Lidar) coordinate system?

How can one change a coordinate system for a .lasd (Lidar) dataset? The file is currently in UTM_Zone_15N and I am trying to convert it to IL_East.
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2answers
845 views

Retrieving average building height in urban areas

I am looking for a way to collect data on the height profile of some cities over time. I don't need to produce a detailed 3D reconstruction of cities, nor do I need to detect and measure individual ...
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3answers
501 views

Thinning large LiDAR point cloud?

I have a large point cloud (LAS file) and I am trying to thin this using a complex technique. I know it is possible to thin a point cloud using simple techniques such as extracting every nth point. ...
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1answer
80 views

Azimuth greater than 360 in Veloview (Velodyne 32)?

When I use Veloview, freezes at 1 of the frames and examine the data points, why are the azimuths greater than 360 degrees?
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3answers
821 views

Benefits of *.las vs *.xyz or *.ascii when working with LiDAR in ArcGIS for Desktop?

From time to time, we use LiDAR data for modelling in ArcGIS. Previously, we would be supplied either an .xyz or .ascii of the data, but more recently, we are also being provided .las files in ...
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5answers
1k views

Processing full-waveform LiDAR?

Does anyone know of a good software package for processing full-waveform lidar? Also, does anyone know of a good tutorial on processing full-waveform lidar?
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1answer
219 views

Landform design/3D in ArcMap 10.2

Im a self taught ArcMap user working in a small business, so no one to bounce problems off. My aim is this: I would like to be overlay different surfaces, manipulate them, and display them. The ...
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3answers
750 views

LiDAR data density, returns per square meter

How can I compute a raster showing the number of return points per square meter using SAGA GIS or other open source software? My goal is to obtain a mask which would show me the places (cells) ...
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6answers
1k views

Ways to visualize multiple large LIDAR tiles?

I want to load approximately 10 large LIDAR tiles for analysis. I have tried using ArcScene but it appears there is a limit on how much data ArcScene can handle at one time. Each tile is 65-90MB in ...
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2answers
111 views

Identifying LiDAR tiles that are located within boundaries of AOI

I am attempting to replicate the process of creating digital elevation models from raw LiDAR data and have been provided with LAS files covering an approximate 530 square mile county area. However, I ...
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1answer
124 views

Tracking which LiDAR data tiles have been delivered

My company works with LiDAR data for large electrical transmissions systems (thousands of miles in one project). We model the transmission lines and do analysis using CAD and GIS workflows. We break ...
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1answer
68 views

Average of raster elevation based on polygon boundaries

I am attempting to extract and calculate the average height of buildings using LiDAR converted to raster elevation data. I've created a DSM to cover the entire area and I am trying to extract just the ...
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1answer
176 views

Viewing point clouds in bpf format?

Is there any software that can be used to view point clouds in bpf format? My preference is for free software that has low-learning curve for quick visualizations. Currently, I convert bpf to las ...
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47 views

Converting waveform LiDAR to discrete return format, in R?

I have an LVIS waveform LiDAR file which looks like this: head(lidar) V1 V2 V3 V4 V5 V6 V7 V8 V9 [1,] 529437.4 ...
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1answer
2k views

Installing LAStools in QGIS 2.4?

Does anyone know where the Processing menu moved in QGIS 2.4? Specifically, I am trying to install the LAStools box for QGIS following these instructions: ...
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3answers
276 views

Extract DEM and DTM information from LIDAR image using E-Cognition

I´m trying to extract DEM and DTM from a LIDAR file. Currently, I rasterize the image but don´t know which algorithm I need to apply to obtain the DEM and DTM information in different models to be ...
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3answers
144 views

Irregular XYZ point data to raster (TIF) - LASTools alternative?

I am trying to convert my irregular spaced point data (xyz) to a DEM and then, to a raster (geotiff). Because of the irregular spacing I need a triangulation first, right (so, no spaces are in the ...
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0answers
43 views

LiDAR doesn't work in QGIS [duplicate]

I'm having troubles to make LiDAR work in QGIS, the instructions are quiet clear and it appears in my processing dialog but when I try to run "lasview" it just doesn't do anything, not even an error, ...
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0answers
48 views

Create a raster dataset containing the number of returns from a las file? [duplicate]

I already created DEMs, DTMs, DSMs from a LiDAR (LAS) file with a little help from the internet. However, right now I'm kind of stuck in my research. I want to create a raster file which contains ...
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2answers
2k views

Drawing irregularly shaped boundary polygon around set of LAS points using ArcMap?

I am working with a set of LAS data which is irregularly shaped, picture a starfish as the point coverage, surrounding the starfish may be water on one side, may be more land elsewhere but no points ...
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2answers
125 views

Convert from shapefile or raster formats to LAS (preferably free)

I am looking for a solution to convert either from ESRI shapefile format to LAS or from a common raster format to LAS. I have access to following software: ArcGIS 10.2 for Desktop (arcinfo with ...
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4answers
4k views

How to clip LAS data using shapefile polygons and open source software?

I am trying to clip or filter lidar files (las, xyz) using a shapefile that contains multiple polygons. Is there open source software that can do this spatial operation? My las files are enormous, ...
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1answer
742 views

Open-source reader of Leica C10 terrestrial LiDAR proprietary file format

I have a Leica C10 terrestrial LiDAR (laser scanner) system. The system creates and stores point cloud data in a proprietary .bin file. Currently I have to use Leica's proprietary LiDAR software, ...
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1answer
246 views

GeoReference XYZ point cloud

I am looking for help. I have done a little bit of geo-registration of images with QGIS. But now, I have been handed some LIDAR data in PCD format (basically x,y,z), But it is not geo-referenced. I ...
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1answer
50 views

How to write a python code for Add Feature Class To Terrain using interface?

I am trying to write a code that creates a Terrain from lidar data (LAS). The problem is that the inputs are in Feature Dataset in GDB but I don't know how to write code so that using an interface. I ...
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1answer
258 views

Workflow for generation of contours with LiDAR data and OCAD

I am updating our maps for an orienteering club in Illinois. I was very excited to find out that we have access to .las lidar data in 2000x2000ft files. I checked out OCAD11 and it can handle .las ...
5
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2answers
238 views

Sun azimuth on shaded relief LiDAR maps

I have a LiDAR map and want to change the view so that the ground shadow is manipulated (looking for archaeological anomalies). I think it is the sun angle that I need to alter but I don't know how. ...
5
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1answer
889 views

Calculate flow path with QGIS

I am trying to replicate my erosion model in ArcGIS for Desktop in QGIS 2.4. I tried to calculate the upstream distance along the flow path for my agricultural field using QGIS. I did the equivalent ...
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2answers
249 views

Cleaning blocks pattern from urban LIDAR (blocks uplifted from streets)

We have a 1-meter LIDAR DEM from a city. A small subset can be downloaded from this link: This screenshot shows raw DEM with gray palette (darker belts are streets, and greyish and whitish ...
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1answer
50 views

Setting colour on point cloud data from raster

I was reading this article: 14 ways to take charge of lidar data. Number 12 states that you can change the colour of your point-cloud data by using a raster image. Does anyone know the process for ...
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3answers
2k views

Optimize nearest neighbor query on 70 million point cloud on SQL Server 2008

I have about 75 million records in a SQL Server 2008 R2 Express database. Each is a lat long corresponding to some value. The table has geography column. I am trying to find one nearest neighbor for a ...
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1answer
203 views

Converting LAS 1.4 to 1.2

LIDAR files were released for major part of Slovenia few months back in zlas format. Decompressed LAS format is 1.4 version. I have tried many options how to generate DEMs and had some success in ...
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2answers
1k views

Combining high resolution and generalized hillshade rasters to produce enhanced shaded relief?

I often add LiDAR data to a map along with a shaded relief. Most of the time I have to generalize the LiDAR DEM depending on the scale of the map. Still, there is often too much detail and mountain ...
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3answers
1k views

What are limits on ArcScene and TINs from LiDAR?

I am trying to load anywhere from 5 to 10 LiDAR TINS into ArcScene. I am using ArcGIS Desktop Evaluation (student) 9.3.1. I just built a new computer with a AMD Phenom II X6 1090T six core processor, ...
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1answer
73 views

Using lastile in QGIS

I want to tile one large las tile into a few minor. But I just can't get it done. My original las file have around 30 million points and I want to get 6 smaller las files with 5 million points in ...
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1answer
109 views

Deleting anomalous points in *.lasd using ArcGIS for Desktop?

I am using ArcGIS 10.3.1 for Desktop. I have a raw .las file that I have brought into an ArcGIS .lasd file format. The raw data has several anomalous points; i.e. the maximum elevation for any point ...