Dave Tewksbury Department of Geosciences Hamilton College Clinton, NY On the Cutting Edge Albuquerque 2013

 Seeing the Earth in unprecedented detail. On the Cutting Edge 2013

 To assess risk and drive research Toe Jam Hill fault scarp Waterman Point scarp beach uplifted during 900 AD earthquake 15 km west of Seattle Haugerud, Weaver, and Harless ( On the Cutting Edge 2013

LiDAR – Light Distance and Ranging Aircraft location known to within few cm using GPS base stations. Aircraft attitude determined by Inertial Measurement Unit. Laser scans the surface at 100,000 to 200,000 pulses per second Oregon LiDAR Consortium ( On the Cutting Edge 2013

Crosby, Christopher, 2009 (opentopography.org/index.php/resources/education)  Travel time combined with known location and attitude of laser platform plus scan angle allows calculation of precise location of each return point. On the Cutting Edge 2013

Crosby, Christopher, 2009 (opentopography.org/index.php/resources/education) LiDAR data  Aircraft flight results in laser scans in zig-zag pattern within swath.  Points not arranged in a grid.  Pulse rate high; point spacing commonly 1 m or less.  Swaths overlap; data density highest in overlaps. On the Cutting Edge 2013

Each laser pulse can produce multiple returns by reflecting off several surfaces in its path  red= 1st return  yellow = 2nd return  green = 3rd return Oregon LiDAR Consortium ( Each return defines a point in space with a unique set of X-Y-Z coordinates At left, point cloud view of tree, colorized by LiDAR return: On the Cutting Edge 2013

Jason Stoker, USGS EROS On the Cutting Edge 2013

Key Concept Data is a Point Cloud with each point occupying a specific X, Y, Z position in 3D space On the Cutting Edge 2013

Point Cloud with each point occupying a specific X, Y, Z position in 3D space Point cloud symbolized by elevation Florence Oregon LAS data downloaded from OpenTopography viewed in ArcGIS 10.1 with 3D Analyst extension On the Cutting Edge 2013

ASPRS Classification Codes Class numbers are not necessarily return numbers On the Cutting Edge 2013

Hamilton College hillshaded raster derived from first return points Hamilton College hillshaded raster derived from classified ground points On the Cutting Edge 2013

LiDAR Data Sources

The handout is a “cookbook” for processing the data All the data is on the DVD which should be copied to the C drive Work at your own pace and I’ll be around to answer questions/solve issues You really cannot learn this by watching someone do it. On the Cutting Edge 2013

NOAA Digital Coast LiDAR – Bathy data Hillshade with semi-transparent orthophoto in ArcScene On the Cutting Edge 2013

On the Cutting Edge 2013