PU (phase unwrapping) is the key step and important problem in DEM (digital elevation model) extraction and the measurement of surface deformation of InSAR (Interferometric synthetic aperture radar). The CKFPUA ...PU (phase unwrapping) is the key step and important problem in DEM (digital elevation model) extraction and the measurement of surface deformation of InSAR (Interferometric synthetic aperture radar). The CKFPUA (conventional Kalman filter phase unwrapping algorithm) can obtain reliable results in the flat terrain areas, but it caused error transmission not making the accurate inversion of surface deformation information in the steep terrain. Considering this situation, so it needs to introduce topographic information for guiding phase unwrapping. Here the 90 m resolution DEM data have been used and it is obtained by SRTM (shuttle radar topography mission) measured jointly by NASA (National Aeronautics and Space Administration) and NIMA (National Imaging Mapping Agency) of U.S. Department of Defense. This paper presents a SD-KFPUA (Kalman filter phase unwrapping algorithm) based on SRTM DEM. With SRTM DEM directing InSAR image to implement phase unwrapping, the speed and accuracy are improved. By analyzing with the conventional Kalman filter phase unwrapping algorithms, it is shown that the proposed method can achieve good results in particular to improve unwrapping accuracy in the low coherence region.展开更多
Various platelet function tests are currently used to identify responsiveness to antiplatelet therapy. 176 ACS patients were enrolled and Linear regression and Kappa consistency analysis showed there was a significant...Various platelet function tests are currently used to identify responsiveness to antiplatelet therapy. 176 ACS patients were enrolled and Linear regression and Kappa consistency analysis showed there was a significant but moderate correlation between platelet inhibition rate and a significant but fair agreement between high clopidogrel on-treatment platelet reactivity tested by light transmission aggregometry and thrombelastography.展开更多
基金Acknowledgments The research is supported by the National Science Foundation of China (40874001) and National 863 plans projects of China (2009AA12Z147). The authors would like to express thanks to ESA (European Space Agency) for providing ENVISAT satellite data.
文摘PU (phase unwrapping) is the key step and important problem in DEM (digital elevation model) extraction and the measurement of surface deformation of InSAR (Interferometric synthetic aperture radar). The CKFPUA (conventional Kalman filter phase unwrapping algorithm) can obtain reliable results in the flat terrain areas, but it caused error transmission not making the accurate inversion of surface deformation information in the steep terrain. Considering this situation, so it needs to introduce topographic information for guiding phase unwrapping. Here the 90 m resolution DEM data have been used and it is obtained by SRTM (shuttle radar topography mission) measured jointly by NASA (National Aeronautics and Space Administration) and NIMA (National Imaging Mapping Agency) of U.S. Department of Defense. This paper presents a SD-KFPUA (Kalman filter phase unwrapping algorithm) based on SRTM DEM. With SRTM DEM directing InSAR image to implement phase unwrapping, the speed and accuracy are improved. By analyzing with the conventional Kalman filter phase unwrapping algorithms, it is shown that the proposed method can achieve good results in particular to improve unwrapping accuracy in the low coherence region.
基金Beijing Higher Education Young Elite Teacher Project(Grant No.YETP0064)from Beijing Municipal Education Commission
文摘Various platelet function tests are currently used to identify responsiveness to antiplatelet therapy. 176 ACS patients were enrolled and Linear regression and Kappa consistency analysis showed there was a significant but moderate correlation between platelet inhibition rate and a significant but fair agreement between high clopidogrel on-treatment platelet reactivity tested by light transmission aggregometry and thrombelastography.