Combination of Multiple Repeat Orbits of ENVISAT for Mining Deformation Monitoring

In conventional differential radar interferometry (DInSAR), the ground surface displacement can be measured along the line-ofsight. In order to measure the vertical and horizontal displacements DInSAR results of the same deformation derived from at least two different look directions are required. This study utilised the DInSAR results generated from ENVISAT data acquired from three different look angles to determine the 3-D displacement vectors resulting from surface deformation due to underground mining. However, The ENVISAT results showed ambiguous phases due to high phase gradients in the differential interferogram. The newly acquired ALOS/PALSAR data is also used here to demonstrate how the high phase gradient problem can be overcome by using interferometric signals with longer wavelength and finer imaging resolution.