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In this paper we investigate the possibility to exploit TOPS data to measure ground displacement movements by means of Differential SAR Interferometry (DInSAR). Several critical points (i.e. coregistration) have to be faced during the data processing since, due to the TOPS signal characteristics, the interferometric chain is very sensi-tive to small implementation errors. The obtained results will be compared with the ones conventionally re-trieved when applying DInSAR on stripmap data. Finally, the potential of DInSAR measurements, when com-bining TOPS and Stripmap data by means of point-like scatterers, will be also analyzed.

This paper presents a methodology to process airborne interferometric SAR data to measure surface velocity fields of temperate glaciers. First, a solution based on multi-squint is proposed to estimate residual motion errors (inaccuracies of the navigation system on the order of a few centimeters) in the case of non-stationary scenes. Afterwards, an efficient methodology to derive surface velocity fields with airborne systems is expounded, where the line-of-sight displacement is estimated using differential interferometry, and the along-track component by estimating the azimuth coregistration offsets. The necessary steps to finally obtain the 3D surface velocity field are also presented, as well as the possibility to combine different acquisition geometries. Airborne interferometric SAR data acquired by the Experimental SAR system of DLR over the Aletsch glacier, located in the Swiss Alps, are used to evaluate the performance of the proposed approach.

This paper presents airborne DInSAR results using a stack of 14 images, aquired by the E-SAR system of DLR during a time span of only three hours and fifteen minutes. An advanced differential technique is used in order to retrieve the error in the digital elevation model (DEM) and the temporal evolution of the deformation for every coherent pixel in the image. Furthermore, some modifications in the differential processing chain are included in order to deal with the existence of the so-called residual motion errors, which play a similar role as the atmospheric artifacts in the spaceborne case. The detected deformation of a corner reflector and of some agricultural fields allows to validate the proposed techniques to measure deformation phenomena with an airborne platform.