SUPER-RESOLVING SAR TOMOGRAPHY USING DEEP LEARNING

Synthetic aperture radar tomography (TomoSAR) has been widely employed in 3-D urban mapping. However, state-of-the-art super-resolving TomoSAR algorithms are computationally expensive, because conventional numerical solvers need to solve the l₂-l₁ mix norm minimization. This paper proposes a computationally efficient super-resolving TomoSAR inversion algorithm based on deep learning. We studied the potential of deep learning to mimic a conventional l₂-l₁ mix norm solver, i.e. iterative shrinkage thresholding algorithm (ISTA), and proposed several improvements of the complex-valued learned ISTA for TomoSAR inversion. Investigation on the super-resolution ability and estimator efficiency of the proposed algorithm shows that the proposed algorithm approaches the Cramer Rao lower bound (CRLB) with a computational efficiency more than 100 times better than the conventional solver.