Fundamental study on resolution enhancement of three-dimensional imaging in SAR tomography

In this report, we provide preliminary results of experimental study on resolution enhancement of SAR tomography. The SAR tomography by using repeat-pass SAR images, or multi-baseline observation, can be regarded as a multi-incident angle imaging array technique. Three-dimensional imaging can be realized with these SAR images (baseline data set) by using direction of arrival (DOA) estimation techniques, such as beamforming (BF) method. In the SAR tomography, limited number of base-lines is the most difficult problem. To overcome this difficulty, we propose to apply the Khatri-Rao (KR) product array processing to the SAR tomography which enhance the array aperture and improves the degrees-of-freedom of the array system. Simulation results are provided to show availability of the KR product array processing in SAR tomography. In addition, indoor X-band model experiments were done in an anechoic chamber of our laboratory to demonstrate performance of the proposed processing.