Monitoring an Extensive Rail Corridor with InSAR
California - USA
Highlights
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The 55-kilometre rail corridor between Hercules and Hayward is vital for transportation, requiring regular monitoring for safety. Traditional inspections are periodic, risking undetected ground or track shifts.
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From December 2018 to November 2021, researchers used advanced remote sensing to track displacement trends, identifying high-risk sections. This data enabled stakeholders to take preventive action, reducing the risk of costly failures.
The Importance of Regular Rail Maintenance
Railway infrastructure is vital for transportation, requiring regular maintenance for safety and reliability. Maintaining major corridors like California’s Hercules-Hayward link is a complex challenge.
The Costs of Maintenance
Maintaining railway infrastructure is costly, with U.S. rail maintenance averaging $5,000–$12,000 per mile annually (APTA). For a 55-km (34-mile) corridor, this amounts to $170,000–$408,000 per year. However, neglecting maintenance risks accidents, delays, and disruptions, leading to even greater financial and human costs.
The Economic Impact of Rail Disruptions
Rail disruptions have significant economic impacts, with Class I freight delays in 2020 costing over $2.5 billion. These losses result from:
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Reduced Productivity – Supply chain disruptions affect industries reliant on timely deliveries.
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Higher Fuel Costs – Idling trains and longer routes increase fuel consumption.
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Missed Deadlines – Delayed shipments lead to penalties and lost revenue.
Passenger rail delays also inconvenience commuters, erode confidence in rail services, and worsen road congestion.
Challenges of Traditional Monitoring Methods
Monitoring a 55-kilometre rail corridor is challenging. Visual inspections are labour-intensive, time-consuming, and offer only a momentary view of track conditions, risking unnoticed ground or track movements between checks.
Limitations of Visual Inspections
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Intermittent Monitoring – Periodic inspections rely on static data, missing dynamic environmental changes.
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Line Closures – Temporary rail shutdowns for worker safety disrupt passenger and freight services.
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Human Error – Subjective assessments risk overlooking subtle signs of track instability.
Physical surveys
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Though more detailed than visual inspections, physical surveys have drawbacks, including:
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Need for specialised equipment and skilled personnel
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Time-intensive processes, especially for long corridors
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Potential disruptions to rail services
Leveraging Remote Sensing Techniques
To overcome these challenges, Geofem utilised Differential Interferometric Synthetic Aperture Radar (DInSAR), a satellite-based remote sensing technology that detects ground displacement with millimetric precision.
Why DInSAR?
DInSAR is ideal for rail monitoring due to:
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Optimal Track Reflection – Metal and ballast materials ensure high-quality radar data.
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Wide Coverage – Satellites assess the entire 55-km corridor in a single dataset.
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Millimetric Accuracy – Detects minute ground movements before visible issues arise.
Data-Driven Insights for Rail Maintenance
Between December 2018 and November 2021, Geofem monitored the Hercules-Hayward corridor remotely, eliminating on-site visits and offering key benefits:
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Uninterrupted Rail Operations – No physical surveys meant no service disruptions.
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Comprehensive Monitoring – Continuous data collection identified trends and anomalies.
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Targeted Maintenance – High-displacement areas were prioritised, preventing major issues.
Benefits of Remote Sensing in Rail Maintenance
From December 2018 to November 2021, Geofem remotely monitored the Hercules-Hayward corridor, collecting three years of displacement data without on-site visits. This ensured:
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Uninterrupted Operations – No disruptions to rail services.
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Comprehensive Insights – Continuous data tracking identified trends and anomalies.
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Targeted Maintenance – High-risk areas were prioritised, preventing major issues.
Advantages of Remote Sensing with DInSAR:
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Cost Efficiency – Reduces on-site inspections, minimises disruptions, and optimises resource allocation.
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Uninterrupted Operations – Eliminates the need for line closures, ensuring seamless rail service.
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Enhanced Safety – Early detection of risks enables proactive accident prevention.
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Scalability – Suitable for monitoring networks of any size, from commuter lines to freight corridors.
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Environmental Benefits – Cuts travel-related emissions, supporting sustainability goals.
The GAIA Project and Geofem’s Role
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Predictive Maintenance – Shifting from reactive to data-driven maintenance using remote sensing.
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Infrastructure Resilience – Continuous monitoring prevents issues from escalating, strengthening transport networks.
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Technological Innovation – Advancing and implementing cutting-edge monitoring solutions.
A Vision for the Future
The use of remote sensing technologies like DInSAR is transforming rail maintenance, providing real-time data for informed decision-making and improved track safety. As demand for reliable, sustainable transport grows, innovations from Geofem and the GAIA Project will be crucial in reducing costs, enhancing safety, and minimising environmental impact.
Data-Driven Insights for Rail Maintenance
The use of remote sensing technologies like DInSAR is transforming rail maintenance, providing real-time data for informed decision-making and improved track safety. As demand for reliable, sustainable transport grows, innovations from Geofem and the GAIA Project will be crucial in reducing costs, enhancing safety, and minimising environmental impact.
Conclusion
Geofem’s use of DInSAR showcases remote sensing’s power in predictive rail maintenance, improving safety, reliability, and cost efficiency.
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