LIDAR

An poster that shows how LIDAR can be used artistically.  Source:  DOGAMI (http://www.oregongeology.org/pubs/ll/p-posters.htm#Honeyman)

I recently attended  a presentation at Portland State University on LiDAR.  The presenter was  Ian Maden, Chief Scientist of Oregon Department of Geology and Mineral Industries (DOGAMI).  He discussed several topics including:  the basics of LiDAR,  planning/ obtaining funding, how foresters have used LiDAR, and a few of DOGAMI's projects.  


I want to give a brief explanation of what LiDAR is but for a better understanding I recommend checking out  DOGAMI's LIDAR page. The US Forest Service is also a great resource for learning more about LiDAR (Link).  LiDAR stand for light detection and ranging (According to Ian it really started out as "Light Radar".)   LiDAR is collected by sending a pulse of lasers from an aircraft to the ground.  The beams then bounce back up to the sensor.  The distance the light traveled can be calculated by knowing how long it takes the light to hit the surface and bounce back to the sensor.  Each pulse is record as a point with the aid of GPS a 3 dimensional location can be recorded for each point. All of the points create a point cloud.  The point cloud can then be used for a variety of purposes. 


One of the major uses of LiDAR is to create a Digital Terrain Model (DEM) that has high resolution.  To create the DEM the point cloud must be converted into a bare surface model.  Another use of LiDAR is to monitor forests and map vegetation.  You can actually identify the top of individual trees and determine the height of a tree using LiDAR.  THE US Forest service has free software called fusion that will allow you to use LiDAR data.  

LiDAR isn't just limited to airplanes.  In fact many companies are using LiDAR on the ground to collect data to create accurate 3D models.  One of my mentors  worked on a variety of projects that has used terrestrial LiDAR.  One of the more interesting  projects was collecting data in a factory so that a 3D model could be created.  The owners of the factory wanted to figure out the easiest way to get new equipment into the factory.  Other uses for ground collect LiDAR include:  Detecting surface change, forest and habitat modeling, and mapping bathemetry of lakes and rivers, as well as making models of crime scenes.    

The amount of information that we can collect by using LiDAR is amazing.  There are so many uses for the data being collected and I'm sure people will come up with new and exciting applications in the future.  I recommend explore the data and learning more about LiDAR I've provided a few links below to help you get started with your exploring.

Links to more information
Video Introduction to LiDAR
Forest Service Fusion Program
CloudCompare Software

Examples of LiDAR Projects
Forest Model
Crime Scene
i 10 Associates
Quantum Spatial