High-Precision Railway Infrastructure Monitoring: Calgary Transit Red Line LRT

Executive Summary

Primary Objective: High-precision automated monitoring of critical LRT rail infrastructure to detect deformation or settlement caused by adjacent multi-story building construction.

The Challenge

Protecting High-Consequence Transit Infrastructure

The Calgary Transit Red Line is a vital piece of public transportation infrastructure. Construction of a multi-story building directly adjacent to the LRT right-of-way introduced significant risks to the track’s geometric stability.

The Problem

Construction activities, specifically foundation drilling and large-scale excavation, can cause localized ground movement. Even millimetre shifts in rail alignment can lead to service disruptions or safety hazards for thousands of daily commuters.

Rigid Tolerance Standards

To ensure safety, Calgary Transit mandated strict monitoring thresholds. Any movement exceeding specified tolerances required immediate reporting and potential work stoppage to protect the integrity of the line.

Technical Constraints

Monitoring had to occur in a live transit environment. Data collection required extreme repeatability and sub-centimeter precision to distinguish between minor thermal expansion and actual structural settlement

The MSI Approach

High-Order Laser Scanning & Automated Analysis

Integrated Workflow:

MSI established a mobile office vehicle to process data while traveling. Processing commenced immediately post-flight, with teams working through the night to ensure stakeholders had actionable data by the next day.

Technical Precision:

Utilized a helicopter-mounted LiDAR sensor with terrain-following technology. This allowed the aircraft to maintain a constant altitude relative to the steep canyon walls, ensuring a uniform point density of 100+ pts/m2 on the bare earth surface.

Results

Accountability & Data Performance

Mission Success:

Successfully executed 130 snow free epochs throughout the life span of the project.

Geometric Accuracy:

Achieved an average Vertical Root Mean Square Error (RMSE) of 3.8 cm

High-Resolution Visuals:

Delivered orthophotos at 4cm resolution, enabling remote visual inspection of rock bolts, mesh, and structural fatigue.

Change Detection:

Developed an interactive Change Detection Layer showing differences within +/- 10 cm between epochs, allowing for the immediate identification terrain movement or slide precursors.

Centralized Data Management:

Designed a comprehensive GIS web database to centralize all deliverables, providing a single "source of truth" for movement trends over the 32-month project lifespan.

Geographic Reach: A North American Footprint

While our headquarters remains in Calgary, our operational reach has expanded alongside our technical capabilities. In 2005, we began by serving Alberta and British Columbia. Today, MSI is a cross-border geospatial partner with the proven ability to mobilize in diverse and extreme environments.

info@msciences.ca

LRT Monitoring