Preparing DOT products from Terrestrial Static LiDAR
Client/partner
A Canada based firm providing LiDAR based services and solutions to several of their clients.
Category
Road & Highway
Project Scope
The project scope involved extraction of road assets and line work with 0.1 foot accuracy. We then prepared a geodatabase out of it with the necessary attributes along with a surface model of the project corridor.
Input
Georeferenced static LiDAR, project specification, and seed file.
Project Initiation
Static LiDAR passed the quality check process. Project scope and schedule were agreed upon with the client.
Feature Extraction
- Because of the large size of data it was split into smaller blocks making it easier to process.
- The edge of road, paint marks, curb-gutter, back of gutter, edges of side walk, and median were captured in 3D.
- Guardrails and barriers alongside the road were extracted to accurately represent the height.
- Building footprints and stair cases were vectored at ground level.
- Lines for the doorways were draped to the surface.
- Breaklines were placed between buildings and the back of the sidewalk.
- Breaklines for ditches, drains, planters, and other features were placed at ground elevation.
- Road signs and signals were symbolically presented at respective ground elevation with descriptive text.
- Billboards, milepost markers, lamp posts, poles, fire hydrants, delineators, manholes, benches, trash bins, and utility boxes were placed at ground height with descriptions.
- Overhead utility lines were strung within the project limit.
- Key points for the ground were displayed in a 2x2 foot grid.
- Points that were overlapping or very close to the breaklines were removed.
- A quality check was performed to ensure that breaklines do not cross each other.
- The line features, point features, and cells were then imported into a personal geodatabase for the project area.
Surface and Contour
The surface model was generated from the breaklines and key shots using Bentley InRoads. The lines and points were triangulated and checked for possible spikes. Contours at 0.2 foot and 1 foot intervals were created for quality checking purposes.
Project Output/deliverable
- A personal geodatabase consisting of line and point features with specified attributes.
As-Built Modeling From Terrestrial Static LiDAR Scan
Client/partner
A US based firm providing LiDAR based services and solutions to several countries.
Category
3D modeling from static LiDAR
Project Scope
The project scope involved as-built modeling of the dam, associated infrastructure, surrounding cliffs, mountains, and water. Everything had to be modeled as a solid and converted to mesh enabling the client to make a 3D print of the dam. The challenge of this project was to create a precise model without gaps so that the geometry of the dam and other surroundings matched the data given.
Input
Georeferenced static LiDAR scans
Project Initiation
Static LiDAR passed the quality check process. The units of the model were verified with the client. Project scope and schedule were agreed upon with the client.
Feature Extraction
- Because of the large size of the data it was split into smaller blocks which were easier to work with.
- Man-made features of the dam were created using solid style modeling.
- Surrounding terrain was modeled using breaklines and points. Underwater terrain was modeled to show an accurate representation of the depth.
- Water was modeled on either side of the dam at its respective height.
- It was ensured that there were no gaps in the model and that it was truly flat.
- Everything was then converted into a mesh.
Project Output/deliverable
- Unified and watertight solid model of the dam in Microstation DGN format.
- Unified and watertight mesh model of the dam in .STL format.
Preparing As-Built Drawings from Terrestrial Static LiDAR
Client/Partner
Azimetry’s partner was a Canadian based LiDAR survey company providing services to engineering and architectural firms.
Category
BIM from terrestrial static LiDAR
Project Scope
Prepare as-built site plans, floor plans, interior elevation plans, exterior elevation plans, reflected ceiling plans, and a roof plan for a multistory, 40 X 40 meter building with a parking garage, commercial units, and residential units.
Input
- HDS LiDAR
- Layer file for plan layout
Project Initiation
LiDAR accuracy was checked, questions and concerns were clarified by the partner, a schedule and a detailed scope was prepared and agreed to with the client.
Project Execution
- Curb and gutter lines surrounding the building were extracted from LiDAR.
- Street sign locations, parking structures, billboards, parking curb stops, and concrete joints were extracted using line strings and polygons.
- Model key points at the ground or floor were collected creating a 0.1 X 0.1 meter grid.
- Using a Microstation DGN file all line features were extracted from LiDAR including the floor outline, door frames, windows, electrical switches, guardrails, staircases, lighting fixtures (surface mount and recessed), fire sprinklers, exit signs, fire alarm strobe lights, fire extinguishers, HVAC equipment.
Drawing existing plans in standard CADD format
Layout and design plans were drawn from the extracted features. Listed below are the drawings prepared for the project and their elements.
Floor plans
- Main floor and all parking garage level plans
- Exterior and interior walls
- Doors and windows including frame dimensions
- Outline of material changes in floors
- Building fire sprinklers, exit signs, fire alarm strobe lights, and fire extinguishers
- Light switches and heating controls
Ceiling plans
- Ceiling dimensions
- Location of all lighting fixtures
- Sprinkler lines and sprinkler heads
Roof plan
- Floor plan for the top parking level
- Exterior outline of residential tower at roof elevation
Site plan
- Curbs and gutters adjacent to building
- Grates and metal outline of slab top
- Street sign locations
- Outline of parking structures, billboard, and parking curb stops (up to 6 meters from the face of the building).
- Concrete joints
Interior elevation
- Wall elevation including edges of surfaces, doors, windows, panel joints, etc.
- Guardrails, parking stops, and staircases in parking areas
- Outline of vertical screen
- Location of light switches
Exterior elevation
- Wall elevation geometry including edges of surfaces, doors, windows, panel joints, etc.
- Outline of vertical screen
- Outline of building signage
Project Output/deliverables
- CAD drawing files for each of the floors including all of the above listed categories.
Objective
Process lidar data in support of an NERC compliance project along a 586 mile transmission line corridor for a large electrical utility provider in Georgia.
Input
- Helicopter collected Lidar data
- Orthophotos
- Client specifications
Lidar classification and feature vectorization production
- Review input data
- Confirm project schedule with client
- Prepare data for processing using both automated and manual methods
- Classify lidar data as per client specifications
- Vectorize features as per client specifications
- String catenaries along transmission line
- QC data
- Deliver processed data to client
Output
- Classified lidar data
- Vectorized features
- 3D catenary strings.
Objective
Process lidar data in support of an NERC compliance project along a 586 mile transmission line corridor for a large electrical utility provider in Georgia.
Input
- Helicopter collected Lidar data
- Orthophotos
- Client specifications
Lidar classification and feature vectorization production
- Review input data
- Confirm project schedule with client
- Prepare data for processing using both automated and manual methods
- Classify lidar data as per client specifications
- Vectorize features as per client specifications
- String catenaries along transmission line
- QC data
- Deliver processed data to client
Output
- Classified lidar data
- Vectorized features
- 3D catenary strings.
