Project Summary

In February 2003, NPA with a team of consultants were appointed by ESA to undertake one of the GMES projects. The project, known as 'Terrafirma' involves the development of an operational service for the pan-European monitoring of terrain motion using the PSI technique from a satellite platform. In Stage 1 of the project the focus was on monitoring of terrain motion in urban environments. To assist in the evaluation of the potential Terrafirma service offering, NPA co-opted a Core User Group to consider user requirements and applications. Arup, as consulting engineers, were appointed by NPA to participate as part of this Core User Group to provide an independent opinion as to the potential application of PSI monitoring in the civil engineering sector.

The Core User Group identified that to achieve a sustainable penetration into the monitoring market, convincing data were required that compared results from the PSI monitoring with those produced by conventional monitoring systems. To this end Arup with NPA undertook an initial comparison of PSI monitoring results with terrestrial monitoring data at a single site.

The Arup study considered a single building (The Treasury Building) on the Jubilee Line Extension Project in central London and semi-quantitatively compared groundtruth data from precise levelling with PSI monitoring results subsequently derived from the archive of radar data. The PSI data was provided to Arup in a fully processed form via NPA. The study considers PSI from viewpoint of a civil engineer, treating the technique as black-box technology. This is consistent with the aims of the Terrafirma project, where the aim is to deliver a monitoring service to a wide range of users who simply want motion data without detail of the underlying technology.

Based on the initial study, the following conclusions can be made: