light detection and ranging - feca© 2013 infotech enterprises lidar stands for light detection and...
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© 2013 Infotech Enterprises. All Rights Reserved
We deliver Global Engineering Solutions. Efficiently. June 7, 2013
Light Detection and Ranging
Rajnish Chauhan
© 2013 Infotech Enterprises
LiDAR stands for Light Detection and Ranging. Initial laser vector is
transformed through a series of reference systems to yield object coordinates
in a chosen Coordinate System
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LiDAR
Types of
LiDAR
Terrestrial
Mobile
Airborne
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Due to its fast data capture and processing, its applications are in various
areas. Some of them are
1. Utilities (Gas, Electric, Water, Sewer etc.,)
2. Floods
3. Coastal Applications
4. Forest Mapping
5. Urban Applications,
6. Cellular Network Planning
7. Mining
8. Corridor Mapping (Rails and Roads)
9. Glacier and Avalanche
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LiDAR - Applications
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LiDAR Benefits
Delivers high accuracy products with effective cost
Quick data collection and processing
Acquisition in all seasons – Leaf on and Leaf off
Enables mapping of larger project area
Provides robust data sets with multiple possible
products
Performs better in vegetated areas than
photogrammetry
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Best LiDAR inputs based on the activity
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LiDAR for Electric Utilities
Airborne Terrestrial Mobile
Substation Transmission Distribution
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Transmission
o LiDAR data helps to simulate the exact scenarios for various purposes by using design
software like PLS-CADD
o LiDAR technology provides accurate elevation models for transmission lines
o LiDAR helps to locate grow-in and fall-in trees for TVMPs to keep utilities in NERC FAC-003
compliance
Substation
o DEM generated by LiDAR point cloud helps in finding the best location for substation
o Terrestrial LiDAR is used to capture all significant information of the substation safely by
reducing potential hazards of having a surveyor at the data point.
Distribution
o Spatial location of poles, transformers, street lights and switch gears can be extracted
o Height and associated feature information can also be extracted for poles & towers
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Value addition for Electric Utilities
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Utilities Business Need
Reliability
Avoid trees contacting the transmission lines
Public Safety
Avoid energized transmission lines from sagging
Forest Fires
Prevent tree related fires
FAC-008 FAC-003 FAC-003
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Utilities Business Drivers
USA
NERC prompts encourages transmission owners to review their VM activities under Reliability Standard FAC-003 and FAC-008.
UK
ESQCR prompts encourages transmission owners to avoid tree-related outages and to review their VM and compliance activities amended under ESQC(A)R 2006.
Australia
Electricity Safety (Bushfire Mitigation) Regulations 2003 and Electricity Safety (Electric Line Clearance) Regulations 2010 are formed to control forest fires and outages
Stringent Regulatory Compliances
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LiDAR Classification
Classification helps in turning off the points related to unnecessary classes to facilitate
easy vectorization and to analyze clearances, accesses, obstacles and hazardous
vegetation encroachment etc.
Ground
Vegetation
Pole
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LiDAR Classification – Huge Data, More Manageable
Difficult to distinguish the features
Easy identification of features
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LiDAR Classification - Clarity
Before Classification
After Classification
Everything looks same in the
unclassified LiDAR and unable to
identify the poles and catenaries in
order to vectorize the data
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We deliver Global Engineering Solutions. Efficiently. June 7, 2013
Infotech’s LiDAR Capabilities
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• Generate and update large data of landbase information for
various counties across the globe through combination of
Photogrammetric and LiDAR technologies
• Used LiDAR for producing highly accurate Digital Elevation
Models ranging from 0.05 meters to 0.5 meter resolutions
• Executed several projects for government clients, e.g. York
County and City of Los Angeles
• Comparative advantage of capturing LiDAR DEM over
conventional photogrammetric collection i.e. 10,000 points /
sec against 1,500 points / hour
Overview
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Services offered
• Post-processing
• Bare Earth Classification
• Feature Classification
• Elevation Modeling
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Process Flow
Post- Processing
Data Models
Classification
Filter
Processing
Last Return
Processing
Digital Surface Models
Vegetation & Canopy
Classification
Building Classification
Utility Classification
Digital Terrain Models
Hydro Models
Transportation
Volumetric
Primary
Classification
Trajectory
Correction
Projection
Parameters
Surface Model
Bare Earth
Model
First Return
Processing
Ra
w L
iDA
R
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Acceptable inputs for processing
• Time stamped trajectory information
• LiDAR point cloud
• Ground Control Points
• Project boundary - AOI
• Point density slicing
• Accuracy
• Other sources – Orthoimagery etc
• Standards or guide lines to follow
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Software Used In Processing Phases
• LiDAR post-processing
o Terra Modeler T-Match
• LiDAR classification
o Terra Modeler
o Terra Scan
o Microstation
• LiDAR management
o Geo-QUE
• FME
o Data Conversions
o Quick hill shade view
o Quality checks and validation.
o New template
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• Analyze Mismatch in Laser inputs o Pre-Processing of inputs and analysis of mismatches in
Flights lines, Trajectory, Laser points etc.
• Apply Corrections to Data Sets: o Correction in accuracy of trajectory elevations such as
fixing of systematic errors in position, orientation
o Correction of heading, d-Easting, d-Northing, roll and pitch
for whole data set
o Correction of heading, d-Easting, d-Northing roll and pitch
for each flight line
o Modify laser points of each interval with a unique Z
correction
• Matching Data sets o Matching of crossing flight lines
o Linking of laser points to trajectory position
o Matching of flight line number to trajectory number
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Capability illustration | Post Processing
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Capability illustration | Bare Earth Classification
Raw Data Edited Data
The bare earth DEM includes all significant visible constructed features if they appear to sit on the earth or
at ground level, e.g. roads built on embankments (including over pipe culverts). Small structures and all
structures built above the ground are removed, e.g. bridges, solid concrete road dividers.
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Bare Earth Classification
• LiDAR post-processing steps yield a cloud of first and last return mass
points
• Classifying last return points which do not represent the terrain yields
Bare Earth Models
• Classifying first return points representing above ground features
(including some ground contact ) yields Surface Models
• Bare Earth Models classified as Bare Earth DEMs
• Surface models classified as Digital Surface Models (DSM)
• Entire ground points can be classified by ground class routines and
algorithms run with Terra Scan
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Raw LiDAR
Bare Earth
Capability illustration | Example
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Vegetation Classification
• Filtered from first return laser points with
classified ground points
• Automatic vegetation / canopy classification
using macro algorithms
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Capability illustration | Example
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Hydro Classification
• Hydro features – rivers, streams, lakes, ponds etc.
classifed by auto algorithms and routines run in
Terra Scan
• Laser points inside the captured hydro features are
classifed to Water Class
• Assign constant elevations to classifed polygon
hydro features
• Placement of Breaklines to delineate the continuity
of the rivers/streams beneath bridges/culverts.
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Classified Hydro
Delineated Hydro
Capability illustration | Example
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Building Classification
• Filtered from first return laser points with classified
ground points
• Automatic building classification using macro
algorithms. Show the extensibility to non-flat roofs
with the help of few manual interactions.
• Routines applied to classify buildings by specifying
the following inputs:
• Minimum size of the building
• Steepest Roof angle
• Maximum empty gap between points belong to
same roof
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Capability illustration | Example
Surface Data with Building
Classified Buildings
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Utility / Transmission Classification
Power Transmission line and corridor mapping:
Laser points are classified to power lines by semi-
auto routines.
Manually extract tower strings.
Wire lines are detected automatically by using
tower strings. Manually classify the pylons, arms
and attachments.
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Capability illustration | Example
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Capability illustration | Example
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Generate the bare earth LiDAR terrain models ranging
from 0.5 meter to 5 meters. The vertical accuracy of
these terrain models are highly precise compared to
conventional aerial photographic DEM
Generate LiDAR DEM by classifying bare earth data
of first return lidar cloud points and the DSM is
generated by extracting the last return of cloud points
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DSM
Capability illustration | Elevation Modeling
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Terrain Modeling
• Bare Earth DEMs are generated by classifying bare earth data of last
return cloud points
• Generate Bare Earth DEMs ranging from 0.075 meters to 0.5 meter
resolutions with suitable grid intervals.
• Generate DEM’s suitable to generate contours of cartographic
standards supplemented with breaklines using aerial, satellite imageries
or lidargrammetry (no associated image).
• Generate DSM by filtering point cloud of first returns.
• Produce DSM products of post spacing ranging from 1m to 5m
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Contour
DSM
DEM
Capability illustration | Example
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Capability illustration | Volumetric Analysis
Identification & delineation of ore dumps Creation of DEM Volume calculation of dump piles Dump Analysis
• Identification of the dump piles
• Area calculation of piles
• Volume calculation of piles
• Change detection of pile health
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Achievable Accuracies :
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Accuracies and Post Spacing Achieved
Scale Point
Spacing
Equivalent
contour interval
Vertical
Accuracy
Horizontal
Accuracy in cm
1”=100 I m 1 ft 10 cm 68
1”=200
2 m 2 ft 20 cm 1.3 m
1”=400
3-4 m 4 ft 40 cm 2.7 m
1”=500 5 m 5 ft 50 cm 3.3 m
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Processing Capacity
Ability to scale up/down resources on demand
Process Capacity /month
Post-Processing <=1000 Sq.km
Bare Earth and elevation Models ~ 1000 Sq.km
All Feature classification ~ 500 Sq.km
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Infotech Edge
Standard Operating Procedures
Knowledge management
Quality Management systems
Global ERP
Process
People
Recruit, deploy and retain best talent
Technology, Tools & Training
Robust, Flexible, Modular Global Infrastructure
• Multi Million hours of experience, strong technical and domain expertise
• Robust and scalable global delivery model and project execution framework
• Predictable engagement with agreed SLAs and proven governance models
• Impeccable quality, first time acceptance and on-time delivery record
• Commitment to long-term sustainable client relationships
© 2013 Infotech Enterprises Limited. All Rights Reserved
We deliver Global Engineering Solutions. Efficiently. www.infotech-enterprises.com
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