Unlocking New Insights into Riverscapes with Drone‐based ...
Transcript of Unlocking New Insights into Riverscapes with Drone‐based ...
Unlocking New Insights into Riverscapes with Drone‐based Laser Scanners
W. Cully Hession
Also: Jonathan Czuba, Charlie Aquilina & Laura Lehmann (VT‐BSE);Bryan Brown & Erin Hotchkiss (VT‐BIOL); Nicholas Polys (VT‐ARC/CS);Peter Sforza (VT‐CGIT); Jonathan Resop (UMD‐GEOG)
Outline
• What is a riverscape?• Riverscapes and complexity• Study area• Lidar background• Drone‐based laser scanner (DLS)• Mapping riverscapes
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https://www.sulisfineart.com/keith‐burtonshaw‐contemporary‐graphite‐drawing‐riverscape.html
What is a riverscape?
The entire spatially heterogeneous scene of the river environment (Fausch et al., 2002)
• Channel morphology• Aquatic habitat• Riparian or streamside vegetation• Floodplains• Spatial/temporal variability
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Laser Scanning
• Light Detection and Ranging (lidar)• Emitting a laser pulse on a surface• Catching the reflected laser back to the lidar pulse source with sensors• Measuring the time laser travelled• Calculating distance from source [Distance = (Speed of light x Time elapsed)/2]
6https://www.yellowscan‐lidar.com
Aerial Laser Scanning (ALS)
• Advantage – Coverage ~ Very large• Limitation – Resolution ~ 0.5 m, Time‐step ~ 6 yrs
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Terrestrial Laser Scanning (TLS)
• Advantage – Resolution ~ 0.01 m• Limitation – Coverage ~ Very small; Mobility challenged
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Drone‐based Laser Scanning (DLS)
• Advantage: Resolution, repeatability, coverage• Limitation: Cost, licensing, etc.
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Pulse Aerospace, Inc. Drone• Vapor35• 30 lbs (drone + batteries)• 5 lb payload• Flight time 35‐45 min• Embedded computer• Flight control software
YellowScan® Core System – Mapper• Integrated w/Vapor35• Multi‐echo LiDAR sensor GNSS RTK• Calibrated IMU, Embedded computer• >450 pts/m2 @ 20‐30 m
ALS vs DLS
• Raw point clouds @ StREAM Lab
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Data Collection ALS Dec 2016 DLS Mar 2017
Point Density (pts/m2) 4.2 455
Point Spacing (m) 0.5 0.05
Total Points ~850,000 ~90,500,000
Habitat Parameters (Ground vs DLS‐based)
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• Complexity• Shading, sunlight penetration• Available cover• Velocity/depth, flow variations• Channel flow status, water surface area• Riffles, pools, sinuosity• Hydraulic habitat• Above‐ground biomass• Floodplain connectivity• In progress….
Websites to look at
• Lidar data• http://www.projects2.cgit.vt.edu/streamlab/
• StREAM Lab YouTube site• https://www.youtube.com/channel/UC4liIdTHkvTnKWpGz7uA5pQ
• ARC Vimeo• https://vimeo.com/visionarium2018
• StREAM Lab• http://vtstreamlab.weebly.com/• https://www.bse.vt.edu/research/facilities/StREAM_Lab.html• http://streamlabvisual.weebly.com/
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