New surveillance system using polarimetric radar for monitoring disastered area

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The purpose of the research project is to develope a new surveillance radar sytem to monitor disastered area using a polarimetric radar. The basic idea is as follows ; the polarization state of scattered wave from normal urban area will be different from that of area in case of disaster auch as earth quake because there will be building collapse. The difference in polarization state will serve as monitoring index to check the extent of disaster. In order to clarify and validiate the proposed method, we tried to use the full vector nature of electromagnetic information. The principle of radar polarimetry based on Sinclair scattering matrix brings us to classify targets by the following items :Characteristic polarization statePolarimetric enhancementDecomposition of scattering matrix into three basic types, sphere, diplane, helix.Polarimetric anisotropy coefficientPolarimetric entropyAt first, we made miniture of buildings in an echoic chamber in Niigata University and used a full polarimetric FM-CW radar system in the X-band to acquire scattering matrix. After the polarimetric calibration of the radar system, it worked as an accurate polarimetric radar.Then, the radar system was used as a new surveillance radar sytem to monitor collapsed buildings in a laboratory measurement. The decomposition of scattering matrix into 3 basic components provided quite satisfactory results, and it was verified the single bounce component increases as collapse increases. The index of polarimetric entropy also supported the similar results. It is confirmed that the radar is effective for monitoring, provided that polarimetric radar is used in a proper condition including precise repeat pass.