The use of InSAR (Interferometric Synthetic Aperture Radar) to complement control of construction and protect third party assets

Summary

Instances of the use of InSAR on the Crossrail project are presented in this case study and the process of working with InSAR data via GIS software is reviewed. Advantages of InSAR include its low cost relative to other techniques, its ability to monitor large areas and the availability of historical data. The limitations of the technique include image frequency, unwrapping errors arising from signal wavelength and the requirement for surfaces with high backscatter of radiation. These limitations mean InSAR is most useful as a tool to monitor pre- and post-construction ground movements, as a complimentary monitoring system to more traditional monitoring methods.

This case study will be of interest to those delivering tunnelling projects who are making decisions about monitoring regimes and systems.