Gordon Associates is a consulting firm providing surveying and engineering services including 3D laser scanning. Laser scanning uses lasers to rapidly capture detailed 3D data on physical environments. It generates dense point clouds that allow clients to access more survey information without additional site visits. Laser scanning is used for applications like as-built modeling, construction monitoring, topographic surveys, and forensic investigations. It provides accurate spatial data that conventional methods cannot access.

1. High-Definition (3D) Laser Scanning
William H. Gordon Associates, Inc.
www.whga.com

2. WHAT IS 3D LASER SCANNING?
Simply stated, a three dimensional (3D) laser scan (also referred to as a High-Definition scan or point cloud)
William H. Gordon Associates, Inc. (Gordon) is recognized as a leading provider of professional consulting services is like an image from a digital camera, except that each and every pixel can be established in a real world 3D
to public and private sector clients in the Metropolitan Washington, DC region. Founded in Northern Virginia in 1976, coordinate system. As compared to traditional surveying methods that field identify individual specific points,
Gordon has assembled civil engineers, land planners, landscape architects, surveyors, and security/law enforcement
High-Definition scanning generates intense regions of points. Accordingly, the surveyor, designer, and/or client
has subsequent access to a much larger database of information should survey requirements later change or
professionals located within a regional network of offices to provide comprehensive, multi-disciplined services to
expand.
address the needs of government and business.
3D Laser Scanning is utilized to accurately capture and store “as-built” or “existing” information for areas ranging
TOP20
WA S H I N G T O N , D C
from mechanical plants to ancient monuments. The scanner captures the information from a scanned area in
a digital format. Once in that format, the user can view, measure, assess, and totally interact with that area as
ENGINEERING FIRM
though they were located within the actual environment. Clients move freely around in this environment, adopt
any chosen viewpoint, and zoom in or out to inspect or measure selected detail. The scanner’s “point cloud” is
like a visualized 3D model reflecting real world features in an accurate, re-locatable coordinate system.
CAPABILITIES
Laser Scanning services provide a higher level of survey data accuracy with greater field efficiency to meet the
diverse needs of architects, engineers, government agencies, contractors, attorneys, etc. Expedited access to
field data from the scanner creates the ability to determine specific dimensional requests more quickly and to
Site Consulting Services Survey & Mapping Services customize deliverables to meet the clients’ needs without numerous site re-visits.
• Civil Engineering • Topographic Surveys
• Landscape Architecture • High-Definition Laser Scanning
Benefits
• Site Security Consulting • Property Mapping Surveys
• Gordon can accurately capture and document a building’s
• Sustainable Planning/Design • Construction Layout interior or exterior to facilitate the architectural design process
• Land Planning • QA/QC Surveys for building construction or renovation. The scan data provides
an alternative to existing documents that may prove incomplete
• Recreational Facility Planning/Design • GIS/Database Development or inaccurate and thus, enhances the designer’s ability to identify
component conflicts. Point cloud data can also be utilized in many
CAD and visualization software packages to create informative
models to give a complete and interactive view of the project.
The modeling information can also assist in evaluating other
parameters, such as sun shading, sight lines, and relational
“Gordon’s mission is to provide value-added professional consulting services associated with mass that may have significant project considerations.
the development and stewardship of land and/or facilities.”
• Gordon can accurately capture and document a facility’s
information, including mechanical equipment, piping, structural
components, treatment works, etc., to establish critical
clearances and/or work spaces. Scan data can be compiled
in many restricted areas where traditional surveying methods
would not be feasible.
• Gordon can accurately capture and document the conditions of
existing structures or sites to establish definitive pre-construction
conditions. These same procedures can be utilized to establish
extensive documentation on historical structures or sites.
Gordon performed 3D Laser Scanning Services at the National
4501 Daly Dr., Suite 200 301 North Mildred St., Suite 1A Gallery of Art in 2007.
Chantily, VA 20151 Charles Town, WV 25414

3. CONTRUCTION MONITORING
Construction may include activities, such as surface grading, bank/slope construction, stockpile/material
quantities, and QA/QC requirements. High Definition Surveys utilizing Gordon’s 3D laser scanner achieve precise
measurements in a fraction of the time conventional surveys require. Gordon’s High Definition Laser Scanning
covers area more thoroughly and quickly and helps address the needs associated with hazardous or complex sites.
Delivery of highly accurate and robust topographic data, combined with true color photographic information,
ensures a comprehensive picture of the construction activities is established.
Stockpile Monitoring
Digital Terrain Model
Gordon performed long-term monitoring of
this stockpile to provide material quantities.
Beginning with a Digital Terrain Model
created from a 3D mesh of the point cloud
(shown right), contours can be created,
Point Cloud and Photo and the volume can be calculated in the
field once all the data is acquired.
Image of point cloud data draped with
digital imagery. Gordon performed a High-
Definition Survey of this site to obtain an as-
built survey of dredge material from Lake
Accotink in Fairfax County, VA. Point cloud
data can be processed into topographic
maps and delivered in a variety of formats,
including Microstation. Laser scanning
was essential to this project because it
kept Gordon personnel out of the dredging
areas, while obtaining topographic data
that would otherwise be unattainable via
traditional survey methods.
Earthworks
Gordon is able to quickly and accurately
scan large areas of excavation to monitor
soil volumes, such as the dam site shown
here.

4. TOPOGRAPHIC SURVEYS
Project: Meyer Elementary School
The use of a laser scanner for typical topographic surveys is becoming more common place with the evolution Gordon’s surveyors performed HDS of this
of fast point cloud data collection, 360° field of views and scripting. The scanner can be programmed to scan former elementary school grounds as a
different parts of the site and point space at each setup using scripts, thus permitting the instrument to work part of a repurposing and planning project
hands-free. Gordon crews utilizing conventional survey equipment, such as robotic total stations, are able for the DC Office of Property Management.
to supplement the survey with data such as invert elevations. As a result, HDS has become cost effective in The points from the scanner point cloud
the preparation of topographic and ALTA/ACSM Land Title Surveys. Additionally, the value-added benefit of can be cleaned of unnecessary noise and
compiling more data than that of conventional surveying reduces the need for future site visits as the project’s augmented with points from a conventional
scope evolves. survey to create a 3D surface model and a
2D topographic map, as shown here.
Project: National Gallery of Art
Located on the block between Constitution
Avenue, Madison Drive and 7th and 9th
Streets, NW is the Sculpture Gardens of the
Smithsonian Institute. Gordon performed
a topographic survey of the grounds
utilizing both HDS and conventional
surveys. Laser scanning provides detailed
topography maps and exhibits for clients
and stakeholders.

5. ARCHITECTURAL
The capture of infrastructure on existing buildings for architectural design purposes is greatly enhanced through
the use of laser scanning. The scanner’s ability to capture data points on surfaces that are otherwise hard
to reach or in unsafe locations is invaluable, especially for structures with complex geometry. Most building
features are vertical or directly overhead, which provide the line-of-sight and angles conducive for a scanner’s
beam. The fact that many buildings may be occupied during survey operations is not problematic since a laser
scanner’s dense data capture enables geometry to be complied even when people move through the scanner’s
field-of-view.
Exterior Renovation Interior Applications
The client needed a cost effective way to This two story atrium at the lobby of this
as-built the exposed face of an existing building would have been difficult to as-
building being completely remodeled. The built if not for high-definition scanning.
building exterior was redesigned to be fitted The captured data was used to create and
with a new glass curtain wall. The remote render a 3D model. Three-dimensional
measuring capabilities of HDS is extremely models of a building such as this one can
cost-effective for most architectural client provide an accurate base for the creation
needs. Gordon surveyors saved the client of a Building Information Model (BIM).
significant time by performing an HDS to
obtain an accurate “as-is” 3D model of the
existing columns. In the office, a reference
plane was established and measured to
the outside column face at each of the 12
stories for engineering of the new glass
curtain wall.
Historical Preservation Concrete Floor As-Built
As a precaution prior to construction of The floor of this new building in downtown
an adjacent high rise building, clients may Washington DC was constructed with
desire to accurately map elements of the an enormous amount of sag. Gordon’s
existing building. Gordon’s surveyors surveyors are able to capture all the
performed a HDS of this historical house imperfections for structures such as this
to capture existing conditions in the event one, which can then compiled into a surface
construction activities caused structural mesh of each floor. A grid of elevations
damage or marred the exterior of the at five foot intervals was created for the
historical home dating back to the 1800s. structural design of these corrections.
Gordon’s data revealed the sag was as
much as 3-inches at the center point of
four columns in this building.

6. MECHANICAL & INDUSTRIAL
The need for fast and precise measurements and industrial applications is critical. Whether managing existing
space, positioning pipes, establishing as-built dimensions or planning new additions, a 3D laser scan provides a
timely, permanent record, critical decisions, and panoramic imagery. Typical facilities that benefit from the use of
3D laser scanning include chemical plants, power stations, water works, gas works, factories, and other industrial
facilities that may have “clean conditions” rooms.
10 Megapixel Image & Point Cloud Wire Frame
Gordon’s high definition 3D laser scanner has A 3D model can be exported as a wire
a built in 10 mega pixel camera to capture frame mesh to AutoCAD, Microstation or
360° panoramic images. The images can other design software. Additionally, the
be draped over the scanned point cloud to as-built wire frame can be imported into
create realistic 3D ortho imagery and .avi facility management information systems
format “fly-throughs”. Point clouds are also and other BIM applications.
applicable for providing “true” dimensions,
pipe widths, angles between two planes,
and plumbness of walls or columns.
3D Modeling Solution
Utilizing state of the art modeling software, 3D “as-is” models of existing plant
Gordon can create 3D models from systems are utilized in retrofits, revamps,
the point cloud for rendering surfaces, interference checking, or clash detection
determining distances/volumes, or locating and reverse engineering. The increased
and identifying objects. This post data accuracy reduces variances in engineering
collection process includes cleaning and construction, helps reduce errors, and
unwanted points from the point cloud, eliminates the need for return visits to the
segmentation and fitting of the geometric project site.
features (e.g., planes, cylinders, cones,
spheres).

7. ROADWAY & BRIDGES
High Definition Surveying utilizing a 3D laser scanner is a fast and safe way to capture as-built information
needed for road and bridge design, inspection, and monitoring. The 3D Laser Scanner can be positioned out of
the flow of traffic, while providing a 360 degree scan of the roadway, intersection, or bridge. The scans are
combined into an accurate 3D model, which is edited to remove scanned vehicles and other “noise” to create the
line work and surface model. The scanning technology allows Gordon to employ safe work zones without lane
closures or impacting traffic flow.
Road Surface Repairs Intersection Improvements
Gordon employed its Scanstation 2 from the A heavily traveled four lane highway is
shoulder of Interstate-66 to capture a four reduced to two lanes prior to crossing the
lane section of the concrete road surface in bridge over the Shenandoah River from
dire need of repair. The data was captured Harpers Ferry, WV. Gordon’s engineers
in two days during heavy traffic periods, needed to design improvements to the
while closing only the highway shoulder. intersection of the access road into a
Point cloud data can be used to create line section of Harpers Ferry National Park
work and surface models for a detailed just before the bridge on U.S. Route 340.
topographic map of roadway projects Gordon surveyors were able to scan the
such as this one. Additionally, the point intersection in one day collecting all road
cloud and digital imagery can identify all features including existing striping without
damaged areas for engineering design. impeding traffic.
Tunnel Repairs Bridge Design
Gordon obtained detailed point cloud data Gordon’s scanner team performed a
of a portion of the Interstate 395 bridge- High Definition Survey of this bridge
tunnel in Washington, DC. Point cloud crossing over Interstate 395 in Virginia.
data was used to dimension and design Three dimensional models of both bridge
replacement granite panels of the bridge- surfaces and understructures were able
tunnel facades. to be scanned in one day from just four
positions.

8. FORENSICS
Most forensic professionals agree that the single most valuable benefit gained from the technology is the ability
for investigators to virtually return to the crime scene and extract out additional measurement and viewpoint data.
This can be done days, weeks, or years later; long after the scene has been released. Scan data is especially
important should the scope and direction of the investigation change, as new evidence becomes available.
Gordon personnel are familiar with law enforcement protocols surrounding crime scene integrity. Our scanning
equipment and process can successfully meet the legal requirements of the Frye and Daubert tests, as required
by the court system. In addition, Gordon’s laser scanning services are recommended by graduates of the Virginia
Forensic Science Academy, which is recognized as one of the top crime scene investigation training academies
in the world.
Crime Scene Preservation 3D Model from Point Cloud
3D laser scan data is not someone’s The data can be modeled into a 3D
reconstructed interpretation of the rendering and exported to other software
scene; it is the scene. Being able to for additional animation programs.
virtually revisit the scene frozen in time
exactly as the first responder found
it provides public safety officials with
a powerful way to visualize and place
themselves into the scene.
Point of View Imagry and Animation 3D Model - Point Cloud Overlay
Recreation of crime scene environments The 3D model helps enhance the visual
can be established from point cloud data effects of the point cloud data.
in the form of still imagery or animated fly-
throughs. This allows investigators, legal
teams, and grand juries to view virtual
tours of the scene from the station or
courtroom.

9. 4501 Daly Drive. Suite 200 | Chantilly. VA 20151 | 703.263.1900
301 North Mildred Street. Suite 1 | Charles Town. WV 25414 | 304.725.8456
w i l l i a m h . g o r d o n a s s o c i a t e s , i n c .