SAR Interferometric Point Target analysis and application to the monitoring of land subsidence in the Venice Lagoon

Abstract

In the Interferometric Point Target Analysis (IPTA) point-like targets that remain phase coherent over time are identified in a sequence of satellite Synthetic Aperture Radar (SAR) images and used to estimate the progressive deformation ofthe terrain with millimetric accuracy. Building upon conventional interferometric SAR techniques, IPT A overcomes atrnospheric delay anomalies and tempora! and geometrie decorrelation by exploring the tempora! and spatial characteristics of radar interferometric signatures collected from point targets widely available over urban areas but that can be also found scattered outside cities and villages. In this contribution the application of IPT A to the monitoring of land' subsidence in the urban and littoral environments of the Venice Lagoon is described. The results achieved using ali the available ERS SAR images acquired between 1992 and 2000 are very significant due to the achieved target spatial and tempora! coverage.