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Dr. Nicholas Coops: Introduction to LiDAR Technology

Published on Jun 16, 2013

Dr. Nicholas Coops provides an introduction to LiDAR for forestry and natural resource management. Terrain elevation was the original intent but our capacity to interpret vegetation heights has moved it from research to operational work quite quickly. Lasers are at the core of the LiDAR technology. Right now it is based on aircraft equipped with LiDAR equipment, flying over the landscape we want information about and recording the returned energy coming back from vegetation and the ground, all at different heights from the airplane. He describes in detail, the technology of the LiDAR survey and how the airplane flight and density of laser pulses give different types of LiDAR data. Filtering of the pulses is required to get a digital elevation model (DEM). LiDAR is point information compared to pixel Information from Landsat. Different GIS techniques are used to interpret the DEMs. From the Digital Terrain Models (DTMs), slope, vegetation class can be interpreted and checked against the DEMs to predict error. He illustrates with some examples how more data and more ground data results in better terrain maps. He describes in detail the four different types of LiDAR: profiling (the early days), (scanning LiDAR) small footprint, large-footprint and ground -based LiDAR. Individual tree scale and plot scale LiDAR are offering forest managers powerful tools to predict biomass production and ecological attributes.

Dr. Nicholas Coops is Canada Research Chair in Remote Sensing, Department of Forest Resource Management, University of British Columbia. His presentation was part of the Wet Areas Mapping Workshop, Calgary, Alberta on Feb. 11, 2013.
 

What is LiDAR?

Published on Feb 28, 2014

Director of Remote Sensing Amar Nayegandhi explains the science and technology behind Light Detection and Ranging (LiDAR) services.

Transcription:
LiDAR can be considered an acronym for Light Detection and Ranging. It is a remote sensing technology that's used to measure distances, and it doesn't act on its own. It actually -- LIDAR typically includes three independently operating technologies. There's LiDAR, which is essentially a giant laser ranging device. The laser-ranging device sends out millions of pulses. Today, they can send out over 400,000 pulses in one second. That technology gives you the distance or the range to the target and there are two other technologies: GPS, which is Global Positioning System, or global navigations systems, that give you the location of the instrument that's holding the LiDAR sensor. The third technology is the initial measurement unit, which is an IMU system and that system is used to measure the pitch, roll, and heading of, for example, an airborne platform. It could also be installed on a installed on a mobile platform like a car or vehicle on the road, or it could be a terrestrially mounted LiDAR system such as those mounted on a tripod. The reason why sometimes LiDAR is the preferred technology to use is that it can map the bare root beneath vegetation better than most other technologies can.
 
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