Fundamental study on angular resolution improvement of SAR tomography by using Khatri-Rao Product virtual array processing

SAR Tomography (TomoSAR) regards multi-baseline observation data as array observation data and realizes three-dimensional imaging by applying direction of arrival (DOA) estimation processing. To improve angular resolution of the TomoSAR with suppressing ambiguity, many repeat-pass data are required. However, it is often difficult to increase the number of data because of the cost. In this paper, we propose to apply the Khatri-Rao (KR) product virtual array processing to the multi-baseline observation data. We show that the KR processing improves angular resolution of the TomoSAR and suppression of ambiguity by using the experimental data obtained by the Pi-SAR2-X.