The functioning of critical infrastructure is essential for the societal and economic well-being of modern societies. To prevent infrastructure degradation, continuous monitoring is required, and persistent scatterer interferometry (PSI) has demonstrated substantial effectiveness for this purpose. It is a well-established method and is used by a wide range of practitioners. However, the operational use of PSI for asset-level infrastructure monitoring remains a challenge for nonsynthetic aperture radar (non-SAR) experts and practitioners. This tutorial provides a practice-oriented guide to PSI for critical infrastructure monitoring and addresses non-SAR experts and practitioners by providing guidance on key decision-making steps, including data selection, processing criteria, and the interpretation of expected tradeoffs and uncertainties, using bridges as a representative application case. The article first reviews SAR fundamentals, clarifies important SAR-related terminology, and explains the principles of the PSI workflow, then discusses key processing decisions related to data selection, datastack creation, and the decoupling of environmental signals from structural response. The article provides guidance for interpreting displacement products and documenting processing assumptions to support reproducible workflows. Finally, it outlines future opportunities enabled by high-resolution, multiorbit, and machine learning (ML)-assisted SAR systems.      «

The functioning of critical infrastructure is essential for the societal and economic well-being of modern societies. To prevent infrastructure degradation, continuous monitoring is required, and persistent scatterer interferometry (PSI) has demonstrated substantial effectiveness for this purpose. It is a well-established method and is used by a wide range of practitioners. However, the operational use of PSI for asset-level infrastructure monitoring remains a challenge for nonsynthetic aperture...     »