Integrated Radar Interferometry for Ground Subsidence Monitoring

This paper reports the progress of the ongoing ESA CAT-1 project (ID 1078). Radar interferometry (InSAR) has been used together with GIS (Geographic Information System) technique to monitor ground subsidence due to underground mining in a test site around the Appin township, southwest of Sydney, Australia. Various digital elevation models (DEMs) are assessed using elevation profiles from ground survey. The best DEM is then employed to remove topographic fringes in the differential InSAR (DInSAR) processing of ERS-1/2 and JERS-1 data. Successful DInSAR results are exported to the GIS and mine subsidence regions extracted. Subsidence profiles derived from the DInSAR results show that JERS-1 repeat-pass DInSAR can achieve +/1 cm resolution for subsidence detection while ERS tandem DInSAR can achieve +/2 mm in the Australian test site, which highlights the importance and urgency of developing a constellation of InSAR satellites now that high quality DEMs are widely available, so that ground deformation can be monitored with much shorter re-visit time.