Wednesday, January 23, 2013

Get Your Head in the Clouds

This is a reprint from an earlier blog (ember 18, 2009) that is no longer available.

Geospatial applications are renowned devourers of information. As new technologies for capturing data are developed, the geospatial applications soon follow. It makes sense as we try to find better and cheaper methods of modeling our world. One of these technologies is LIDAR (Light Detection And Ranging). LIDAR is becoming a common remote sensing technique. It sends out and measures the return of laser pulses to determine distances (as well as other information) in 3 dimensions to essentially generate a 3D view of the scanners environment. The resulting data is a very large group, or cloud of X, Y and Z values (along with other descriptive information depending on the equipment and technique). These point clouds have required specialized software to view and capture information.
Now, subscription AutoCAD Map 3D and Civil 3D users have some new tools available to work with these point clouds. The new Subscription Advantage Packs include tools for viewing and classifying Point Clouds. This can be incredibly useful to geospatial users. At a large private electric utility I used to work for, we used LIDAR as a method to survey electric transmission lines and surrounding vegetation. We were looking for trees that were growing into the lines and cause potential outages.
Clouds1After installing the new Subscription Advantage packs in AutoCAD Map 3D, some new options become available. In the Task Pane’s Display Manager Tab, there is a new option in the Data menu – “Add Point Cloud Data.” Selecting this option opens a file select dialog prompting for an ISD file – a Point Cloud index, or data store file. You create the index from the new Point Cloud Manager.

Clouds2Another new option is in the Tools menu – “Create Point Cloud Index.” This option opens the Point Cloud Manager.
From the Point Cloud Manager, we can add LIDAR data files to create a Point Cloud data store, merge them into groups, set coordinate systems, use filters to classify, create elevation ranges and even create spatial filters.


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Adding the Point Cloud Data will create an entry in the Display Manager tab, and add a new Point Cloud ribbon giving us tools for stylization, exporting and creating surfaces.
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Keep in mind, these data sets are big, and will tax your system resources, so be prepared.
So, get your head in the clouds and check it out. The view is great.
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