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CONDUCTING A LiDAR PROJECT AND WHAT YOU
CAN DO WITH THE DATA
CHRIS GUY
LIDAR PRODUCTION MANAGER
Meeting The Needs Of The Project
Choosing Appropriate System And Platform
Project Planning Methods
Processing Workflow
Resources Necessary To Meet Schedule
Applications
Advantages of LiDAR
Software
Outline
Meeting The Needs Of The Project
Transportation
Contours
Transmission Lines
Contours
Volumes
Buildings
Feature Extraction
Vegetation
Erosion
Deciding Accuracy and Application
Appropriate Platform
Helicopter
Airplane
Train
Boat
Automobile
Tripod
Choose the Correct Sensor
Large area sensor – Leica ALS70
Corridor sensor - Optech Orion
Mobile LiDAR sensor- Optech Lynx
Fixed tripod scanner
Cameras to support the LiDAR
LiDAR Project Planning
Plan based on
Flightline distance limitations
Workable blocks of data
Delivery tiles
Baseline requirements
Control locations
Accuracy
Application
Topography
• Day or Night
Safety considerations
• Leaf on or Leaf off
Application dependent
• Summer, Spring, Fall, or Winter
Most collects done in the spring and fall
Summer collects take place for special
applications such as forestry
Winter collects based on geographic
location
• Weather
• Smoke
LiDAR Project Planning
Establish a Flight Plan
• Altitude
• System PRF
• Scan Angle
• Speed
• Overlap
Standard LIDAR – Nominal 1m point spacing
15 cm RMSEz vertical accuracy
Hydro Enforced breaklines
20 foot nominal widths for rivers
1 acre lakes/ponds
General-use, Meets most needs for LiDAR-based DEM
USGS Compliant LIDAR – Nominal 1m – 2m point spacing
15 cm RMSEz Vertical Accuracy
Hydro Enforced Breaklines
100 foot nominal widths for rivers
2 acre lakes/ponds
Points removed off breaklines in separate class
1m – 3m DEM
Metadata
Processing and Vertical Assessment Reports
High Accuracy LiDAR – 0.7m or more Point spacing
9.24 cm RMSEz
Supplemental 1 foot accuracy specifications
50% overlap for very dense vegetation
Supplemental breaklines
Vertical Assessment Report provided
Requires very good calibration: Keep overlap
LiDAR Specifications
Terrain Impacts Collection and Processing Techniques
Swath Gap?
Possible Void Area
Flightlines with Proposed Base Stations
Data collection as required by client
Contour products
Sample density – 8 points per meter and higher
3-D building extraction
Clients requiring
additional classification
Water
Vegetation
Buildings
Planning Specialized LiDAR
Review and Initiate Project
Area 7,754 square miles
Flying Height 1,500 meters
Ground Speed 160 knots
Flight Line Sidelap 50%
Pulse Repetition
Frequency 70 KHz
Scan Angle 40° (total)
Scan Rate 35 Hz
Proposed Tile Format 2000 ft x 2000 ft
Total Number of Tiles 54,064 tiles
Units US Survey Feet
Project Work Flow
LiDAR Acquisition (field)
Control Survey (field)
Airborne or Mobile
GPS/IMU
Output LAS
Mission Calibration
Build Project
Classify LiDAR point cloud
Create Deliverables
Flight Plan Overlay On Imagery For Estimating
Establishing Control
Check Point Surveys
Five Main Categories
Hard Surface
Low Grass
High Grass
Brush
Forest
What does this mean?
By region?
Point distribution?
Verification of Point Class
Legend High Vegetation Points
Medium Vegetation Points
Bare Soil points
GPS/GNSS Processing
• Launch GNSS Processor
• Convert Raw data files to
GPB format
• Aircraft
• Base Station
• Published Position and
Antenna Height and Type
LiDAR Processing - Processing
Checking Calibration Differences between bad calibration and correct calibration
Unresolved Area Resolved Area
Checking Calibration DZ ortho from several missions
All Points Surface Before Point Classification
Surface After Classifying Points To Ground
Surface From Point Cloud Classified to Ground
Applications
Hydro Breakline Collection Process (LiDARgrammetry)
Additional Classification
• Smooth Water Bodies
• Vegetation - Low, Medium, High
• Buildings - Points, Footprints
More Detailed Line work Buildings, Curbs, Oil Tanks, Road Center Lines
Further Classification Techniques
Class Examples
-Building
-Ground
-Water
-Non Ground
-Above or Below Ground
-Transmission Lines
-Pipeline
-Rails
DAM Management
DSM- Digital Surface Model Intensity Image
Building and Vegetation Extraction
3-D Buildings
Airborne -Planemetrics
LiDAR of Bridge at 0.3 meter collection
LiDAR of Mile High Stadium
Airborne- Security Management
Airborne – As Built
Airborne – Transmission Mapping
Airborne – HCA and Risk Analysis
Pipeline Mapping
Materials calculations – construction
Site Design
Airborne – Change Detection
Contour and Orthorectification Generation
Filtered Bare Earth LiDAR & LiDAR DEM
Bare earth surface model Contours draped on surface Contours
Photography draped over
LiDAR data Contours draped over
orthophotography
Terrestrial LiDAR –Construction and Engineering
44
Terrestrial LiDAR (AEC) Architecture, Engineering, Construction
45
Terrestrial AEC Architecture, Engineering, Construction
46
Terrestial Emergency Management
47
Terrestrial -Transportation
48
Terrestrial -Accident Reconstruction
49
Rail Survey
Rail Survey – Image fused with LIDAR
Terrestrial LiDAR
Levee – Picked up cracks in the pavement on the levee
Terrestrial LiDAR
Geomorphology- Coal veins
Terrestrial and Helicopter
Transmission
3D models and Site design
3D Modeling
Survey-Grade Contour and Planimetric
Data
Advantages of LiDAR over Photogrammetry
Collection day or night
No sun angle requirements
Ground data through canopy
Measure heights of canopy
Accurate surface models in forest
Thank You