Hot answers tagged lidar
10
Commercial:
FME Desktop
" ability to take a point cloud that has no color information on it, and overlay it into an orthophoto to produce a colorized point cloud"
http://blog.safe.com/2012/01/beating-lidar-into-submission-with-fme-2012/
LP360
Add-on to ArcGIS
http://www.qcoherent.com/products/index.html
LP360 for ArcGIS™ (Basic, Standard and Advanced)
...
8
This sounds like Tom Patterson's work on Resolution Bumping GTOPO 30 in Photoshop. The theory is described well enough to be adaptable to other software, though work needs to be done coming up with the specifics. The basic idea is to generalize (blur) one data set, a lot, to emphasize the general shape and hide specific detail and then blend the hi-res and ...
7
There is no way to get floor heights from a lidar pointcloud. Lidar is captured by bouncing lasers off the groundsurface and measuring the bounced back pulses. Therefore there is no way for the lasers to 'see' through the roof of a building and return a floor height.
However, a solution to this may be to classify your las point cloud into ground and non ...
6
A common mistake (that I've made too) is to down-sample a raster using the resample tool with bilinear interpolation. See this answer for an explanation why this is not good. A raster can be down-sampled in three steps.
The first step might not be required. Reproject the raster to the target extents. Use bilinear interpolation, and keep the output cell ...
6
FUSION/LDV is a powerful and solid open source option developed by the USDA Forest Service to analyze and visualize LiDAR data. General information about FUSION can be found here:
Overview of FUSION features:
Generates DEMs from point data
Produces bare earth surfaces from unfiltered points
Displays image data for background reference
Subsamples large ...
5
I provide a number of sample LiDAR files at http://liblas.org/samples that you can download. These are mostly example data, but many are quite interesting. You can use the las2txt utility that libLAS provides (or Isenburg's las2txt version as well) to convert them to XYZ ascii files.
Isenburg's tools also provide a number of fantastic triangulation ...
5
Tips: Note: Your computer has plenty of spec:
Develop a full or partial disk cache whenever possible.
Disk caches allow data to be pre-rendered for optimum ArcGlobe/ArcScene display performance.
Store ArcSDE/ArcScene data sets using the Cube projection
This will avoid pyramid resampling and data reprojection for ArcGlobe.
...
5
Sounds like you're wanting to do this in batch (don't blame you)
As STH said, looks like Global Mapper will indeed do batch conversions. Nice price as well.
FME Desktop can do using the RasterDEMGenerator transformer and a bit of linking with reader/writer, but you'll need the Pro version, not available in the ArcGIS Data Interop extension.
If free is ...
5
Try running the sp_help_spatial_geography_index stored procedure to get details on how your spatial index is being used. You should be able to use something like:
declare @ms_at geography = 'POINT (-95.66 30.04)'
set @ms_at = @ms_at.STBuffer(1000).STAsText()
exec sp_help_spatial_geography_index 'lidar', 'SPATIAL_lidar', 0, @ms_at;
Post the results in ...
5
There are several online videos showing how to use Image Analysis with Lidar data with eCognition.
Image Classification methods are key to extracting the correct data.
http://www.ecognition.com/news/ecognition-tv/
Vegetation (Tree Canopy Extraction)
http://www.ecognition.com/news/ecognition-tv/extracting-tree-canopy-lidar
Building Extraction
...
5
There are a number of places where footprints can come in very handy
Public Sector:
Taxation: As @Mapperz said, taxation is one area. The percentage of
property that is built on is sometimes used as a tax criterion.
Planning: Knowing where structures already exist on property can
help in the planning process due to applied setbacks and minimum
...
5
It all depends on where you draw the line. Regardless, this problem looks like it can be readily addressed using the morphological functions available in Spatial Analyst, especially thresholding (performed with "<" and ">" local operations) and "RegionGroup" to identify and extract components.
Although I do not have access to the DEM to illustrate, the ...
5
2 points per meter is plenty for what you want to do.
I assume the company that is flying the LiDAR is going to develop your solar analysis, digital surface models, etc...? If not, how are you going to do this?
What software are you using? Your computer is plenty powerful, but if you are using incorrect workflows/software it can slow down the processing, ...
5
Sub-centimeter elevation? No.
This article provides a good overview of LiDAR and the associated errors (Range, Position & Orientation).
Operationally, when working with LiDAR data we assume a potential 5-10cm vertical and horizontal error. At times it may be much more accurate, but it's not sub-cm.
5
(The answer is based on my and others' comments above; haven't really tested it)
Store the points as MultiPointZM. The best grid size would probably be dependent on access patterns and you need to do some testing on this. A regular grid with a spatial index should make queries quite fast. If 3d access is important then MultiPointZM could be 3D block ...
4
Methodology for creating accurate drainage networks (and catchments) from high resolution LiDAR DEM?
With regard to generating hydrologicaly correct elevation models, also called drainage enforced, ANUDEM, remains best of breed to my knowledge. It's the program used to generate the Canadian national elevation dataset (CDED, ironically stored as integer-metres). Also the TopoToRaster tool in ArcGIS uses Anudem under the hood (a revision or three behind ...
4
I see "ArcGIS" is a tag, Jakub. Using Spatial Analyst you would simply compute a weighted average of the two hillshades. E.g., the 60-40 mixture could be generated with a calculation like this:
(60*[Detailed hillshade] + 40*[Generalized hillshade]) / 100
If you need it, the Gaussian blur can be executed by running a few circular focal means over a ...
4
GeoServer can supply your Web Application Network KMZ - in real-time.
There is a very good 'Visualize Lidar in Google Earth' page here
http://www.cs.unc.edu/~isenburg/googleearth/
(Martin Isenburg & Jonathan Shewchuk)
key point is:
"we create the 10 by 8 tiling of 10 feet contours gilmer.kmz (c,d) in only 20 minutes using less than 100 MB of main ...
4
West Virginia View has some first/last files here:
http://www.wvview.org/data/lidar/Gilmer/las/
This takes you through a USGS viewer, which links out to other sites (which may not have the design/interface):
http://opentopo.sdsc.edu/gridsphere/gridsphere?cid=datasets
4
For our book "Open Source GIS: A GRASS GIS Approach" we have published a large North Carolina dataset. It contains the raw Lidar data as separated files which you can grab at http://www.grassbook.org/ncexternal/ (Lidar multi-return data).
4
Take a look at:
http://www.census.gov/geo/www/cob/co2000.html
and
http://www.census.gov/geo/www/cob/cs2000.html
for counties and county-subdivisions
hope this helps
Kurt
4
I read about variety of algorithms for the job (ie. as per @Hornbydds link).
I tried couple appoches, and the best results in my case yield Standard Terrain Analysis from SAGA. Here is what I did and why:
Dikes are usually highest feature in the vicinity of river channel, so I turned them into channels by flipping DEM (MapAlgebra DEM * -1 or for ...
4
Hello Processing Full Waveform Lidar,
If you already have the data from a waveform system the best software would be from the vendor of the lidar system.
If it is already processed but you want to do additional analysis - a very popular program for that is MatLab.
The best information available is really found doing a websearch of white papers and ...
4
FullAnalyze is open source waveform software. http://fullanalyze.sourceforge.net/
SPD is a waveform file format with open source processing software. http://www.spdlib.org/doku.php
4
LASTools can perform a ground classification using "lasground" and then can perform some limited feature classification using "lasclassify". The performance and quality of feature classification in point clouds is strongly influenced by the type of landscape collected. Some landscapes just do not lend themselves to acceptable automated results. The best ...
4
Have you worked with US Forest Service's open source software Fusion? It processes LiDAR data in DOS environment.
This software converts ASC files to ".las" or ".lda" (see pages 6 and 23)
I would try the following program command: ASCIIIMPORT (see the manual's page 23).
Here is how you can do it.
Install Fusion (place it at top hierarchy, right under c:).
...
3
You can do this through the ESRI ArcGIS Geostatistical Analysis Extension - there is a section in the help on performing validation on subsets.
You could do the same through GRASS through the R interface. Tomislav Hengl describes in some detail how to do so in his book A Practical Guide to Geostatistical Mapping. It's open access, so the PDF is free to ...
3
The tool lasgrid.exe (README) from LAStools does a "direct" conversion with gridding (without triangulation) very fast. The tool las2dem.exe (README) from LAStools rasters the points via a temporary TIN. Regards, Martin @lastools
3
There's a distinct possibility that ArcScene is running up against the default Win32 process limit of 2GB. Originally, due to this limitation, ESRI was designing their 3D products to max out at around 20 million points.
Update: ESRI support note on the TIN size limitation (~15 million, dated 2008)
3
Intermap have national coverage of DSM data available via Terrain on Demand. It reportedly offers OGC compliant access on a commercial basis.
ESRI also have a beta program offering a global mosaic of elevation datasets, some at 1m resolution. ...
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