Display LiDAR Data - MacOdrum Library · *Note: Lidar Intensity (x, y, z, i) is also recorded with...
Transcript of Display LiDAR Data - MacOdrum Library · *Note: Lidar Intensity (x, y, z, i) is also recorded with...
Lidar (Light Detec on And Ranging) is
a type of remote sensing. It works like
radar, except it uses light or laser beams
instead of radio waves. www.library.carleton.ca/find/gis
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Display Display LiDAR DataLiDAR Data
This Help Guide will show you how to:
ArcMap
Display Lidar data from shapefile in 3D using ArcScene
Display LAS files in ArcMap & ArcScene by crea ng a LAS
Dataset
Global Mapper
Display raw LAS files in Global Mapper in 3D
*Note: Lidar Intensity (x, y, z, i) is also recorded with most lidar data. It records the reflec vity of a surface.
This data can be used to create a geo‐referenced image of the landscape. Lidar intensity can be rela ve to its
surroundings, and it is easily influenced by current condi ons. It should be researched well before use.
*Note: Lidar points are commonly grouped into by 1st returns
and 2nd returns. The 1 returned are also known as the
“Non‐Ground” points since they returned to the sensor first,
meaning they probably reflected off trees or buildings.
Conversely, the 2nd returns are some mes called the “Ground
Returns” since these points took longer to return to the sensor ,
and probably reflected off of the ground.
h p://www.vliz.be/v/images/thumb/2/29/Lidar_fig_03.jpg/250px‐Lidar_fig_03.jpg
Figure 1: A 3D view of ground (red) and non‐ground (green)
Lidar point shapefiles in ArcScene.
The me it takes for the laser to travel from
the sensor (o en mounted on a plane or
helicopter) to the surface and back is used to
calculate the distance to an object.
Lidar can be used to provide highly accurate
eleva on data. The data is collected as points
with X, Y, Z values. These points can be also be
used to create DEMs.
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Displaying LiDAR Displaying LAS files in ArcMap and ArcScene
This demo is using the Carleton University Lidar located at: J:\Carleton_University_Campus\Lidar
Create a LAS Dataset
Open the ArcToolbox and navigate to
Data management Tools>
LAS Dataset> Create LAS Dataset.
2. In the tool window fill out the
required parameters.
3. Press OK when you are done.
ArcMap/ArcScene cannot open raw LAS files. In order to view them, they must be put into a
LAS Dataset. A LAS Dataset can be created in either ArcMap or ArcScene using the steps out‐
lined below.
Browse for the LAS files you wish to add to the Dataset.
Browse to select an
output loca on and
name for the new
Dataset
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Displaying LiDAR Displaying LAS files in ArcMap and ArcScene
This demo is using the Carleton University Lidar located at: J:\Carleton_University_Campus\Lidar
Above: The newly created LAS Dataset containing the les for Carleton Campus. The LAS dataset
will be iden fied by the file extension .lasd.
Above: You can change the colour ramp of the dataset, and pan and rotate your view.
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Displaying LiDAR Displaying LAS Files in Global Mapper
This demo is using the Ville De Ga neau 2007 Lidar located at:
J:\_O awa_Ga neau_Region\Ville_de_Ga neau\Lidar_2007\LAS\LAS_Full
Global Mapper has the advantage that it can read .LAS files without having to create a LAS
Dataset like ArcMap does. This makes it idea to quickly view Lidar in LAS format both in 2D
and 3D.
Load the LAS files into Global Mapper
Click and drag the LAS files from a folder in
Window Explorer into Global Mapper.
2. An Unknown Projec on window will appear claim‐
ing there is no projec on associated with the LAS
file. Click OK to con nue to the Select Projec on
window.
3. Select the appropriate projec on and datum. Then
click OK
4. Next, the Lidar Load Op ons window will appear.
Accept all the defaults by clicking OK.
Right: The LAS file will loaded into Global Mapper.
This shows Parliament.
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Displaying LiDAR Displaying LAS Files in Global Mapper
Viewing the LAS files in 3D
Click on the Show 3D View bu on on the top toolbar in Global Mapper.
This will open up the 3D view in a new window.
Use the rotate and move bu ons to pan around this 3D view.
Below: Shows how much detail Lidar can capture,
even the hydro lines!
Right: The Parliament Buildings and O awa River .
Above: The Ga neau side of the O awa River.