InSAR monitoring for infrastructure
Civil infrastructure demands the highest standards of monitoring - early detection of ground movement can prevent service disruption, avoid costly emergency repairs, and protect public safety. InSAR provides systematic surveillance across infrastructure networks, identifying problems at stages when intervention is still straightforward.
Power generation and distribution
Power stations, substations, and transmission corridors all require stable foundations.
InSAR monitors ground conditions across these assets, detecting settlement, subsidence, or slope movement that might affect structural integrity or operational safety.
For nuclear energy facilities, where ground stability requirements are particularly stringent, InSAR provides the continuous and precise measurement capability needed for long-term condition assessment.
GEM have applied InSAR monitoring for the nuclear energy sector through EDF Energy, focusing on decommissioning applications where understanding historical and ongoing ground behaviour informs safe dismantling strategies.
InSAR has been used to effectively monitor major infrastructure projects in London, including Crossrail and Thames Tideway.
This example from London Power Tunnels 2 (LPT2) demonstrates minor subsidence along the tunneling route (movement scale is anonymised), with greater subsidence in soft ground sections compared to the more competent chalk.
Tunnelling and underground construction
Major tunnelling projects create surface settlements that must be monitored and managed to protect overlying structures.
InSAR provides the measurement density needed to characterise settlement troughs and identify buildings experiencing differential movement.
Our research team at Imperial demonstrated InSAR's value for tunnelling applications through retrospective analysis of the Lee Tunnel construction in East London. The study identified a drift-filled hollow that the tunnel boring machine subsequently encountered - a feature that could have been detected through historical InSAR analysis prior to construction.
Transport infrastructure
Roads, railways, airports, and ports represent major investments requiring ongoing condition monitoring.
InSAR identifies embankment settlement, cutting slope movement, and broader subsidence affecting transport corridors.
The technique's wide-area coverage is particularly valuable for linear assets, where ground conditions may vary significantly along route length.
GEM have worked with National Highways to develop operational InSAR guidance, install and monitor InSAR corner reflectors at an active landslide adjacent to the M25, and deploy our novel drone-based radar system for high-resolution imaging.
InSAR corner reflectors at Flint Hall Farm, Surrey. Installed to provide strong radar reflectors for the monitoring of an active landslide adjacent to the M25.
Dams, water infrastructure, coastal and flood defences
Dam safety monitoring demands continuous measurement over the full structure and its surroundings.
InSAR monitors embankment deformation, abutment movement, and reservoir-induced effects across the entire facility, complementing traditional instrumentation with spatially comprehensive data.
Sea walls, flood barriers, and coastal protection structures operate in challenging environments where ground conditions may change over time.
InSAR tracks settlement and movement of defence structures and their foundations, supporting maintenance planning and identifying sections requiring intervention.