Airport Obstacle Limitation Surveys

Project Snapshot

Project Overview

Introduction

From March 2022 to April 2024, Underhill Geomatics Ltd. (UGL) was contracted by the Yukon Government to update Obstacle Limitation Surface (OLS) surveys for nine certified airports across the territory: Whitehorse, Dawson City, Watson Lake, Old Crow, Teslin, Mayo, Faro, Burwash, and Beaver Creek. The objective was to transition each airport from TP 312 4th Edition to TP 312 5th Edition standards—an update that introduced significantly stricter requirements for obstacle-free airspace.

To meet these demands, UGL adopted an innovative approach using the DJI M350 RTK UAV paired with the YellowScan Mapper+ LiDAR system, producing highly detailed 3D datasets of the complex terrain and airspace surrounding each airport.

Project Challenges

• Complexity of TP 312 5th Edition – The updated standard required precise interpretation and adaptation for each airport’s unique runway configuration and surrounding terrain. Ensuring accuracy in every model was critical, as even a single missed obstacle could impact aviation safety.
• High-Volume Data Management – LiDAR surveys generated dense point cloud datasets. Spatial analysts needed to meticulously compare these datasets against each OLS surface to identify obstacles with zero tolerance for error.
• Extensive Regulatory Requirements – Operating UAVs in controlled airport airspace required detailed regulatory approvals and coordination—adding substantial complexity for UAV pilots and project planners.

Underhill’s Approach

UGL implemented a modernized methodology tailored to the unique challenges of Yukon’s remote and rugged environment:

• UAV LiDAR Technology Deployment – The DJI M350 RTK equipped with a YellowScan Mapper+ LiDAR payload was used to efficiently capture high-density 3D data across each airport’s obstacle environment.
• New Technical Workflows – The team developed new Standard Operating Procedures for:
  • UAV flight planning in controlled airspace
  • LiDAR data processing and classification
  • OLS modeling and surface generation
  • Obstacle comparison and reporting for Transport Canada
• Staff Training & Capacity Building – Training sessions ensured analysts and field staff could confidently interpret LiDAR outputs and build accurate, compliant OLS models.

Notable Outcomes

• 41 UAV LiDAR flights completed, covering approximately 1,600 hectares across nine airports.
• Nine fully compliant OLS plans produced in accordance with TP 312 5th Edition National Standards.
• Significant reduction in field time compared with traditional survey methods.
• Improved data richness, resulting in more reliable and comprehensive obstacle identification.
• The project was recognized with a David Thompson National Geomatics Award in 2025 for innovation.

Technical Highlights

• High-Accuracy LiDAR Data – The YellowScan Mapper+ system delivered dense point cloud datasets with exceptional detail, enabling precise modeling of natural and man-made obstacles.
• RTK-Enabled UAV Platform – The DJI M350 RTK offered stable, repeatable flight performance in remote northern environments.
• 3D OLS Modeling – Analysts developed detailed, airport-specific OLS surfaces in accordance with TP 312 5th Edition, comparing them directly against LiDAR-derived terrain and obstacle data.
• Advanced Data Processing – New workflows enabled efficient handling of massive point cloud files, reduction of noise, classification of obstacles, and automated detection of OLS penetrations.

Project Impact

This project set a new precedent for the use of UAV LiDAR in aviation-related surveying, demonstrating:

• A faster, safer, and more cost-effective method of collecting obstacle data in remote northern regions.
• Enhanced accuracy and significantly improved airspace safety assessments for Yukon airports.
• A scalable model for modernizing OLS surveys across Canada as airports transition to TP 312 5th Edition.
• Advancement of UGL’s internal expertise in UAV operations, LiDAR processing, and regulatory compliance.

The successful execution of this project highlights Underhill Geomatics’ commitment to innovation and technical excellence in the evolving field of geomatics.