On the rooftop of a bustling retail hub, hundreds of vehicles use the parking facility daily. Following a season of heavy rainfall, water accumulation on the rooftop raised concerns about the building’s structural stability and drainage performance. Re-designing a piece of commercial infrastructure requires a clear understanding of existing site conditions, risks, and potential alterations. In response, Norsat provides a drone solution that allows property managers, construction crews, and distributors alike to evaluate site conditions without disrupting busy operations.
Challenges of Traditional Methods
Traditional inspections methods include manual measuring tools, field notes, and visual assessments conducted on foot. However, this presents several practical challenges for active commercial sites.
Manual surveying often requires partial closure of parking areas to allow personnel to safely place equipment and move throughout the site. For commercial properties, this disrupts daily operations, reducing available parking for customers or tenants, and increasing liability exposure. In addition, traditional inspections frequently deliver incomplete site coverage, as shadows from rooftop structures and wet surfaces following rainfall can create inconsistent lighting that distorts visual measurements. When subjective visual assessments miss signs of drainage issues, maintenance is often delayed, driving higher long‑term repair costs.
The Drone Setup
The drone operation was conducted at a rooftop parking structure within a commercial logistics center and retail hub in Richmond, BC. The project was delivered for a Property Management Group working in coordination with a Structural Engineering Consultancy. The objective was to safely collect accurate site data for parking layout optimization and post-rainfall drainage inspection without interrupting parking operations.
The DJI Matrice 400 was chosen for its ability to operate safely in busy environments. It supports high-resolution aerial imagery, capturing photos at approximately 2 cm per pixel, which is essential for producing accurate measurements of specific features needed for site redesign. Additionally, the platform’s compatibility with LiDAR sensing made it well-suited for post-rainfall inspection, as LiDAR measures surface elevation using laser pulses rather than visual estimates. This allowed the team to reliably identify subtle slope changes and low-lying “ponding” areas on darker areas where standard photography fails.
The Drone Operation
A detailed flight plan was created to ensure complete coverage of a 2374m2 rooftop surface. Autonomous flight paths were pre-programmed to account for obstructions like HVAC units, ventilation systems, and drainage vents that can create “shadows” and leave gaps in the data. Prior to capturing images, flight parameters were planned to achieve high data density across the entire rooftop parking structure. This included calculating appropriate image overlap ratios so that each section of the roof was photographed multiple times from different angles.
To ensure the digital model accurately represented real-world dimensions, Ground Control Points (GCPs) were incorporated into the projects. Prior to flight, physical marks were placed at clearly visible locations across the rooftop.
Data Analysis
Following data acquisition, all high-resolution RGB images captured by the DJI Matrice 400 were imported into the DIJ Terra, the software for turning aerial images into maps and 3D models. High-precision Aerial Triangulation (AT) was performed to solve the exact orientation of each image in a 3D space. The software identified common features between overlapping images and used them to create distortion-free reconstruction. Once the initial model was established, GCPs were imported and identified within the images. DJI Terra’s automated GCP identification tools were used to rapidly locate the physical markers.
Our end results generated both a high-resolution 2D Ortho mosaic (DOM) and a Digital Elevation Model (DEM), providing a precise overhead view of the parking layout with details of drainage paths and “ponding” zones. During this stage, temporary obstacles like vehicles or debris are automatically removed, isolating the true ground and permanent features of the site.
Integration with End User Workflow
Norsat’s deliverables are designed to integrate directly into the tools already used by property managers, engineers, and facilities teams.
CAD Workflows
The engineering-grade DOM is imported directly into CAD software and used as a precise base map of the parking structure, streamlining the construction process. As DOM is georeferenced and captured at centimeter-level accuracy, property managers and designers can measure site dimensions directly on screen. This also allows teams to digitally test layout changes, such as converting standard stalls to compact stalls or adjusting aisle widths, before physical work is done on site. For intensive projects, a faster turnaround time allows construction crews to move from assessment to planning, improving project timelines overall.
Revenue Optimization
Beyond technical workflows, the drone solution supports several business decisions. Accurate measurements enable property managers to optimize every square meter, often allowing 5-10% more parking slots in the same footprint. It also improves bidding and procurement. Painting, paving, and roofing contractors quote directly from verified dimensions rather than estimates, reducing the risk of over quoting and revenue loss.
The Future of Urban Planning
As cities expand, drone‐based urban planning is enabling a safe and efficient approach to parking management by using high-resolution imaging and other advanced techniques. The DJI’s insights can be integrated into asset management systems, allowing property and facility managers to review the exact conditions of individual parking stalls or drive aisles, better anticipating smart budgeting decisions.
If you are ready to improve safety, reduce risk, and learn more about drone-assisted urban planning, please reach out to Norsat!
