Limitations of Persistent Scatterer Interferometry to measure small seasonal ground movements in an urban environment

Abstract

London Clay, which underlies the majority of Greater London, has a high shrink-swell potential that can result in damage to foundations and surface infrastructure due to seasonal expansion and contraction of the clay. Currently, surface movement as a result of shrink-swell is not monitored in London, meaning that the magnitude and cyclicity of these movements is poorly understood. Persistent Scatterer Interferometric Synthetic Aperture Radar (PSI) data provide highprecision line-of-sight displacement measurements at a high point density across urban areas,

Monitoring Littoral Platform Downwearing Using Differential SAR Interferometry

“…This routine image acquisition frequency provides an unparalleled ability for long-term monitoring, accuracy and data accessibility. The use of long time series (multitemporal) InSAR analysis provides a tool for monitoring small-scale ground deformation and change in a range of different environments, such as for tunnelling projects in urban environments [16][17][18][19][20][21], building subsidence monitoring [22], surface deformation detection [23], mapping interactions between geology and urban development [24], monitoring CO 2 storage [25], or monitoring agricultural areas [26]. Being an active sensing system, SAR imaging operates independently of the sun and weather, giving continuous information without disturbances of rain or lack of sunlight.…”

Measurement and monitoring

“…The sixth paper (by Provenzano et al, 2020) moves from the surface and shallow subsurface to deep marine slopes where excess pore pressures can develop from continuous deposition above, leading to instability. From the deep sea to remote sensing of surface displacements using satellites high up in the sky is the focus of the final two papers (by Bischoff et al, 2020 andScoular et al, 2020) which show how effective his can be and also discuss limitations in certain environments.…”

“…As mentioned in the previously described paper, there are many potential applications that could be investigated by assessing ground movements using satellite data. Scoular et al (2020) focus on the potential for measuring seasonal ground movements in an urban environment using SAR technology, with a specific emphasis on the shrink-swell behaviour of London Clay. The magnitude of ground movements from shrink-swell characteristic of London Clay depends on a number of factors such as climate, temperature, season and presence of nearby trees.…”