1393 Ste-Catherine West
Client / Collaborator
DMA Architectes
Sector
Architecture, Commercial
Location
Montreal
Services
Relevé LiDAR, Relevé par drone, Photogrammetrie
Mandate
As part of this commercial project, DGTL was commissioned to carry out a detailed 3D scan of the building’s exterior, as well as part of its interior. In this context, DMA entrusted us with the 3D scanning of 1393 Ste-Catherine West to produce an accurate reference set for the architectural team.
The aim is to accurately define all interior levels and document the current condition of the building envelope, so that consultants can identify any potential issues that are invisible to the naked eye.
Mandate
As part of this commercial project, DGTL was commissioned to carry out a detailed 3D scan of the building’s exterior, as well as part of its interior. In this context, DMA entrusted us with the 3D scanning of 1393 Ste-Catherine West to produce an accurate reference set for the architectural team.
The aim is to accurately define all interior levels and document the current condition of the building envelope, so that consultants can identify any potential issues that are invisible to the naked eye.
Proposition
GNSS Georeferencing and Control Network
We measure control points using a high-precision GNSS system to establish a robust anchor to the project’s coordinate system. Control points placed on the envelope are then measured with a high precision and high accuracy total station to limit LiDAR and drone photogrammetry drift to only a few millimeters. Those points are also attached to the georeferencing previously provided by the GNSS.
This step ensures a stable reference for all data acquisitions and achieves a control network with a margin of error of 1.67mm over 50m.
Terrestrial LiDAR scanning
A terrestrial LiDAR scan is conducted on the building’s envelope to capture the details of the façades, the openings, and architectural features. This process provides an accurate record of the existing conditions while preserving the building's rich geometric detail. All scan stations are registered and adjusted to the survey control network to ensure consistency, precision, and overall accuracy across the entire project.
Drone Scanning
We conduct a photogrammetric survey using a drone equipped with a high-resolution camera, allowing us to document hard-to-reach zones, which are difficult to access from the ground. The images acquired are captured from a variety of angles, over the course of multiple pre-programmed and manual flight missions. The images are then tied to the primary control network.
With these images, we generated orthoimages with a resolution of 1mm per pixel, and a point cloud that accurately represents the observed surfaces.
Deliverables
Hybrid Coloured Point Clouds
Delivery of a colour point cloud generated from terrestrial LiDAR and photogrammetric data. These two methodologies, applied in a complementary manner depending on the areas of the building, enable the production of a comprehensive point cloud covering the entire envelope as well as part of the interior spaces.
Constrained by the control network, it provides an accurate and reliable measurement basis for analyses, inspections and any future work.
Quality Report
Production of a 17-page quality report that accompanies the deliverables. It outlines the methodologies and technologies used throughout the project. The report also includes images taken during the survey, tables showing target locations, and comments on weather conditions.
