With 9,876 miles of route and 2,578 stations, the UK’s rail sector managed 1,385 million passenger journeys in FYE March 2023. A significant increase of 39.9% over the previous year. In the same year, Network Rail, the rail operator in the UK, spent £2.1 billion on maintaining its assets. This was part of their total expenditure of £15.9 billion.

Operating and maintaining a large rail network requires continuous monitoring and investments around the year which costs dearly, both monetarily and in time. InSAR (Interferometric Synthetic Aperture Radar) not only reduces the time and cost of monitoring but also enables asset managers and engineers to monitor the entire network at scale with up to mm/year level precision. Let us look at a few other ways InSAR can benefit asset managers and engineers in the rail industry. 

Wide area coverage and near real-time reporting
 
InSAR increases measurement coverage by providing thousands if not millions of data points depending on the size of the selected area, allowing engineers to monitor the whole rail network at scale. The data is updated after each satellite acquisition providing near-real-time reporting for the asset in question or wider network. The combination of wide-scale and near real-time monitoring enables a shift towards proactive, preventative maintenance, saving on expensive emergency remediation works.
This high-precision monitoring capability allows for early detection of potential problems and timely preventative measures. Infrastructure companies and engineering firms, amongst others, use InSAR data to monitor different assets such as commercial, and residential properties, large mining sites, entire road, and rail networks and even water utility networks.

Access to historic movement data over the asset and beyond the boundary fence 

Traditional monitoring methods require manned surveys and in-situ equipment and provide movement data from the date of installation. InSAR data, on the other hand, provides both ongoing and historical movement data. This helps engineers build a comprehensive understanding of past movements and their impact on the surrounding area. By using InSAR alongside traditional monitoring methods, asset managers and engineers have a much better understanding of how the ground moved historically, and how it is moving in real-time, across both large and small areas.Assessing the impact of ground movement outside of the right of way could be difficult. InSAR helps overcome this limitation because it can look beyond the boundary fence since it requires no installation on the ground. This helps asset managers to assess the impact of nearby landscape changes on the asset, that may have been missed with in-situ monitoring methods installed in a narrow rail corridor.

Enabling safe monitoring with reduced risks  

InSAR data provides ground movement insights to mm/year precision. Thus, enabling geotechnical engineers to understand possible geological hazards with high accuracy. Early detection of such granular shifts in the ground mitigates safety risks for both passengers and personnel. SatSense's dataset also allows asset managers to pinpoint areas for priority maintenance, which results in optimal resource allocation with lower maintenance expenses and fewer boots on the ground.

Building machine learning models to better predict failures  

SatSense’s advanced machine learning models can analyse large InSAR data sets and look for patterns to identify assets most at risk of critical failure. This helps asset managers direct proactive maintenance measures to key areas, preventing costly downtime and emergency remediation works. This ultimately improves passenger and infrastructure safety across the entire network. 

Overcoming coverage challenges with corner reflectors  

Whilst InSAR is a powerful tool, like other remote sensing techniques, the technology does have its limitations. InSAR works best in urban areas and rural areas with sparse vegetation. Densely vegetated areas pose much more of a challenge. To overcome this challenge, we can install corner reflectors. A corner reflector helps by back-scattering radar waves to the satellite, enabling coverage in areas where there previously may not have been. Once installed, the reflectors are self-sufficient, require no electricity and are very low maintenance. This makes them a cost-effective solution to overcome this limitation.

InSAR as a complimentary technique 

While InSAR has many advantages over traditional monitoring methods. It is best used as a complementary technique which ensures continuous remote data collection, helps analyse movements at both small and large scales, allows us to look beyond the boundary fence, and allows a company to prioritise areas for maintenance. 


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About SatSense’s InSAR solutions 

SatSense is a leading provider of InSAR data and solutions. We’re changing how you access and interpret satellite ground movement data. Our mission is to make this once-expensive dataset affordable, accessible, and easy to interpret. We do this by providing high-quality InSAR data through our data visualisation portal; Satsense Analysis.If you would like to know more about SatSense’s InSAR solutions, please email us at contact@satsense.com or contact us here



Frequently Asked Questions

1. What are the main challenges in monitoring a large rail network? 


Monitoring thousands of miles of rail track is a major operational challenge. It requires continuous, significant investment in both time and money, with UK's Network Rail spending £2.1 billion on maintenance in 2023. Traditional methods like manned surveys and on-site equipment can be costly and often struggle to provide a complete picture of the entire network's stability in near real-time.


2. How does InSAR differ from traditional rail monitoring methods? 


InSAR offers several key advantages over traditional techniques. Firstly, it provides comprehensive coverage, monitoring the entire rail network at scale rather than just specific points. Secondly, it offers historical movement data from before any on-site equipment was installed. Finally, because it's a remote sensing technique, InSAR is non-invasive and can see "beyond the boundary fence" to assess the impact of nearby landscape changes, which is often a blind spot for equipment installed in a narrow rail corridor.


3. How does InSAR enable proactive maintenance on railways? 


InSAR enables a shift from reactive repairs to proactive maintenance in two ways. First, its high-precision, near real-time data allows for the early detection of subtle ground movements that could indicate a future problem. Second, advanced machine learning models can analyze large InSAR datasets to identify patterns and predict which assets are most at risk of critical failure. This allows asset managers to direct maintenance to key areas, preventing costly downtime and emergency remediation.


4. Does InSAR work in vegetated areas along the railway? 


While InSAR works best in urban and sparsely vegetated areas, densely vegetated sections can pose a challenge. This limitation is overcome by installing corner reflectors. These low-maintenance devices are placed in areas with poor coverage and help by reflecting the satellite's radar waves back, enabling accurate monitoring where it would otherwise not be possible.


5. Is InSAR a replacement for traditional monitoring techniques? 


No, InSAR is best used as a powerful complementary technique. While traditional methods provide essential on-the-ground data, InSAR adds the wide-area context, deep historical insight, and continuous remote data collection that traditional methods lack. By using both together, asset managers and engineers can get a much more comprehensive and accurate understanding of their network's stability.