LIDAR and Ortho Imagery
Provide Critical Information for Transmission Power lines
The impact of the massive August 14,
2003, electrical power blackout in the Northeastern United States and southern Ontario was significant on both sides of the Canada/U.S.
border. The loss of power and the inability to provide electricity to an estimated 50 million affected people [m1]cost the
United States and Canada
more than $10 billion. While this is the largest outage ever experienced in North America
to date, power-related disturbances continue to cost $25 - $180 billion annually.
To reduce the likelihood of future
system blackouts, the National Energy Reliability Commission (NERC) created standards to prevent and mitigate the impacts
of future cascading blackouts. NERC is strengthening standards compliance by formally tracking the completion of its recommended
actions.
One such recommended action is the
development of a standard on vegetation clearances, for which NERC will evaluate vegetation management procedures and results.[m2]
Vegetation management is one of the largest maintenance functions of electric utilities, costing in excess of $2 billion annually.
Many electric utilities have established
that the use of LIDAR and aerial imagery are invaluable tools for vegetation management. Not only do these technologies improve
the efficiency and effectiveness of identifying dangerous trees and vegetation encroachments; they also aid in the predictive
modeling of vegetation growth patterns.
Hundreds of thousands of miles of electric
transmission lines will need to be surveyed, much of which will require repeat surveys to address vegetation management issues
associated with the new NERC requirements. Additionally, LIDAR and aerial imagery technologies can assist utilities in collecting
transmission facilities information, such as right-of-way data and the location of towers and lines, buildings and roads.
NERC has adopted very detailed vegetation
management guidelines that, if not followed, could lead to significant monetary sanctions. Utilities are complying with applicable
vegetation management standards and regulations by collecting LIDAR and imagery data necessary to provide digital vegetation
clearances, hazardous trees, vegetation encroachments, terrain features, span lengths, sag distances and structure heights.
LIDAR and image surveying of power
lines provides actual, complete and high-precision elevation and image data of the power line and the surrounding terrain
and vegetation. Utilities can glean a wealth of critical information from these high-resolution, high-density data sets with
the right tools and expertise.
One of the world’s pioneers in
the use of aerial LIDAR/image surveying of electric power transmission lines is TopoSys GmbH, Biberach, Germany.
A leading LIDAR service provider and sensor system manufacturer for more than 12 years in Europe,
TopoSys has developed a line of LIDAR/imaging systems complemented by TopPIT, a pre-and-post processing software that streamlines the entire workflow from pre-flight planning to
final deliverables. The traditional deliverables the TopoSys systems generate include:
* Lidar data point clouds of first
and last echo
* Digital surface model (DSM) of first
and last echo (grid width 0.10 m to 2.00 m)
* Digital terrain model (DTM) of last
echo (grid width 0.10 m to 2.00 m)
* Intensity data
* Image data RGB and NIR (true-ortho
images, resolution down to 0.20 m)
In addition, within the final processing
steps of the LIDAR and ortho image data in TopPIT, supplementary value-add procedures are able to generate:
* Detailed and precise vectorized data
of power lines, conductors and structures
* Cross and longitudinal sections based
on raster datasets and high-density point clouds
Details and 3D information of power
lines such as sags, pylon centre lines, cable f* ixations and attachment points.
* Determination of clearance distances
for power lines, railways and motorways
* Vectorized data based on high resolution
true-ortho images
* Data available in common file formats
such as DXF-, DGN- and SHP-Files
TopoSys’s PowerLiner provides
tools for 3D visualization, as well as the capability to check results interactively. With the PowerLiner software package,
the extraction and vectorization of single power lines can be easily determined, as can 3D coordinates such as pylon positions,
cable fixations, attachment points (intersections) pylon centre lines, lower
cross arm edges, power lines and lowest point per field/sag and several other details. [m3] And, because many of these processes
are automated, the data are available quickly.
Three qualifications make TopoSys the
only LIDAR system manufacturer that can provide all the aforementioned capabilities to mapping/LIDAR service companies:
1. TopoSys offers the complete turnkey
LIDAR/Imaging system, which includes GPS, IMU, data storage, flight planning, LIDAR and the RGB/CIR camera allows the collection
of high-resolution, high-density, precise data sets simultaneously. Additionally, the German-engineered, extremely stable,
space-frame construction results in the most stable, durable and dependable LIDAR/Imaging systems.
2. TopoSys offers TopPIT, the pre-and-post
processing software that streamlines the entire workflow from pre-flight planning to complete final deliverables. The high-quality
data from the TopoSys sensors streamlines and automates the creation of traditional deliverables and value-added products.
3. TopoSys’s 12 years of practical application experience as a service provider is built in to systems, software and
support for its customers’ LIDAR mapping business.
The advanced systems TopoSys utilizes
-- such as the fixed-beam deflection of the fiber-based scanner -- has eliminated all mechanical errors introduced by mirror-based
scanner systems. The fiber-based scanner provides much greater reliability and is the most precise scanner system world-wide.
The overlapping measurements and the uniform scan pattern allow for exact detection of objects and line objects such as power
line cables and polygon structures and results in much better representation of small vertical objects. Vertically stacked
objects such as individual power line cables can also be identified.
Electric energy has effectively become
the very life-blood of society. To that end, it appears just as self-evident that the same preventative maintenance efforts
that avert a stroke or heart attack in humans should be the same common sense that prevents power blackouts and their devastating
impact on human lives and economic activity. Aerial LIDAR and ortho imagery can provide the critical information to assist
electric utilities in providing safe, secure and economic energy – the energy that drives our individual lives and the
entire world. Now, NERC has provided additional incentive to the utilities by implementing detailed vegetation management
guidelines and monetary sanctions for noncompliance. This will open the floodgates and utilities will no doubt begin implementing
LIDAR and ortho imagery-derived information products into their daily operations.
