Synthetic aperture radar (SAR) tomography (TomoSAR) extends the synthetic aperture principle into the elevation direction for 3-D imaging. The resolution in the elevation direction depends on the size of the elevation aperture, i.e., on the spread of orbit tracks. Since the orbits of modern meter-resolution spaceborne SAR systems, like TerraSAR-X, are tightly controlled, the tomographic elevation resolution is at least an order of magnitude lower than in range and azimuth. Hence, super-resolution reconstruction algorithms are desired. The high anisotropy of the 3-D tomographic resolution element renders the signals sparse in the elevation direction; only a few pointlike reflections are expected per azimuth-range cell. This property suggests using compressive sensing (CS) methods for tomographic reconstruction. This paper presents the theory of 4-D (differential, i.e., space-time) CS TomoSAR and compares it with parametric (nonlinear least squares) and nonparametric (singular value decomposition) reconstruction methods. Super-resolution properties and point localization accuracies are demonstrated using simulations and real data. A CS reconstruction of a building complex from TerraSAR-X spotlight data is presented.     «

Synthetic aperture radar (SAR) tomography (TomoSAR) extends the synthetic aperture principle into the elevation direction for 3-D imaging. The resolution in the elevation direction depends on the size of the elevation aperture, i.e., on the spread of orbit tracks. Since the orbits of modern meter-resolution spaceborne SAR systems, like TerraSAR-X, are tightly controlled, the tomographic elevation resolution is at least an order of magnitude lower than in range and azimuth. Hence, super-resolutio...     »

Synthetic aperture radar, Differential synthetic aperture radar tomography (D-TomoSAR), 3D imaging, elevation direction, Image reconstruction, 3D tomographic resolution element, L1-norm regularization, azimuth-range cell, point localization, spaceborne SAR systems, super-resolution reconstruction algorithm, tomographic SAR inversion, tomographic elevation resolution, Anisotropic magnetoresistance, Control systems, Radar tracking, Reconstruction algorithms, Compressive sensing (CS), radar imaging, radar resolution, tomography, Signal resolution, TerraSAR-X, image resolution, remote sensing by radar, spaceborne radar, Azimuth, compressive sensing, urban mapping     «

Synthetic aperture radar, Differential synthetic aperture radar tomography (D-TomoSAR), 3D imaging, elevation direction, Image reconstruction, 3D tomographic resolution element, L1-norm regularization, azimuth-range cell, point localization, spaceborne SAR systems, super-resolution reconstruction algorithm, tomographic SAR inversion, tomographic elevation resolution, Anisotropic magnetoresistance, Control systems, Radar tracking, Reconstruction algorithms, Compressive sensing (CS), radar imaging...     »