Terrafirma products offer a new and unique way to monitor and detect terrain motions. However, the process itself is complex and subject to several variables that can impact the quality of results. A number of activities have therefore ensued (some outside Terrafirma) to 'validate' the reliability and accuracy of PSI. This part of the Terrafirma website details these validation activities.

Main Terrafirma validation campaign:

The Terrafirma Alkmaar/Amsterdam Validation Project: This major 9-month activity is being conducted as part of Terrafirma. Using two contiguous areas in the Netherlands, one of gas production, the other of new metro tunnelling, the project is not only making detailed comparisons of the PSI processing output from the Terrafirma service providers, but also making comparisons of the PSI output against groundtruth - thus validating both the 'process' and 'product' stages of Terrafirma output.

Other significant validation activities:

Jubilee Line Extension inter-comparison: As part of Terrafirma, this limited project focused around the relatively small area of the Treasury Building in London. It compared the processing from NPA, TRE, Altamira and Gamma against high quality groundtruth collected during tunnelling for a new extension to the London metro system.

PSI Codes Cross Comparison and Certification (PSIC4): This ESA-funded project compared the output from eight InSAR providers, four of which were Terrafirma service providers. Processing over a difficult mining site in France was conducted in a completely 'blind' fashion with the processing teams having no knowledge of the site, its extents or the terrain motion phenomena to be mapped.

Provence inter-comparison: This small project, as part of Terrafirma, analysed the 'slant-range' data output from the Terrafirma service providers involved in the PSIC4 project.