David Webb- VWCC
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LIDAR, LiDAR, LIDaR, lidar and LADAR(laser altimetry).
Light detection and ranging
Laser Imaging, Detection and Ranging
Combining the words light and radar
My most common thought about the
subject….
LIDAR Types
 Airborne
 Topographic
 Bathymeric
 Terrestrial
 Mobile
 Stationary
Stationary
Easter Island Moai
http://trl.trimble.com/docushare/dsweb/Get/Document-421274/
LIDAR – Airborne Topographic
 Active Remote Sensing
method.
 Laser pulses are reflected
from objects on or near
the ground.
 XYZ data collected.
 High density of data
points collected.
http://www.fs.fed.us/pnw/pubs/pnw_gtr768.pdf
LIDAR Returns
 Multiple returns.
 First is the highest
object.
 Up to five (5) returns per
pulse.
 Last is not always the
ground.
http://resources.arcgis.com/en/help/main/1
0.1/index.html#//015w00000041000000
LIDAR Attributes
Classification
Classification Value
Classification Type
0
Never Classified
1
Unassigned
2
Ground
3
Low Vegetation
4
Medium Vegetation
5
High Vegetation
6
Building
7
Noise
8
Model Key
9
Water
10
Reserved for ASPRS Definition
11
Reserved for ASPRS Definition
12
Overlap
13–31
Reserved for ASPRS Definition
File Types
 LAS – specification for a point cloud file format with
x,y,z and other attributes.
 ASCII – original format for LIDAR data.
 LAZ – lossless LIDAR Compression.
http://www.laszip.org/
 Data we will use compressed from 164 mb to 29 mb.
 LAS Dataset –LAS storage for use in ArcGIS.
 Convert into TIN, DEM, contours and others.
Uses of LIDAR
 Flooding
 Coastline erosion- changes
 Vegetation
 Forestry
 Improving accuracy and resolution of basemaps.
 Planning
 Urban Growth
Find Data
 Virginia- William and Mary hosts state LIDAR
http://www.wm.edu/as/cga/VALIDAR/index.php
 USGS CLICK: Center for LIDAR Information
Coordination and Knowledge (not compressed!)
http://lidar.cr.usgs.gov/
 LIDAR LINKS for mappers
http://www.lidarbasemaps.org/
Why LIDAR?
 Jamestown
 Civil War Redoubts
 Coastal LIDAR
http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~26954~1100253:Battery-Sawyer,-Va---Battery-Pruyn,
Colonial Parkway
 Three Civil War era forts.
 Document condition.
 Student service learning and fieldwork.
Project
Colonial Parkway Redoubt Fort