Highly accurate DSM reconstruction using Ku-band airborne InSAR

We present a newly developed airborne InSAR system incorporating a novel phase unwrapping algorithm, capable of retrieving a highly accurate Digital Surface Model (DSM). The SAR sensor system, with a spatial resolution of 30 cm, is carried on an airborne platform which has 2 antennas placed in a baseline length of 1 m. We have established a DSM reconstruction processing technique, which includes the new "Iterated Conditional Modes-Minimum Cost Flow" (ICM-MCF) phase-unwrapping algorithm. The ICM-MCF algorithm finds a locally optimal configuration of unwrapped phases under a well-characterized statistical model of the terrain and noise. An experimental field observation was carried out in Tsukuba, Japan. The DSM was generated, and the height accuracy of the SAR-DSM was evaluated by comparing with laser profiler data. For 50 cm x 50 cm mesh, an accuracy of better than 50 cm in height was confirmed.