Long term deformation monitoring using advanced multi-pass InSAR techniques ─ differential TomoSAR and SqueeSAR

Speaker: Dr. Xiaoxiang Zhu (DLR)

Time and Date: 10:00-11:00, Jan. 9, 2014

Place: Room 1101, East Guanghua Building, Handan Campus

 

 

Abstract

In this seminar, advanced multi-pass InSAR techniques, namely Differential SAR tomography (D-TomoSAR) and SqueeSAR, will be presented for long term deformation monitoring of urban and rural areas, respectively.

 

In urban environment, severe layover effect is expected. D-TomoSAR was originally proposed for estimating linear motion of multiple scatterers inside a pixel. Motion, however, is often nonlinear (periodic, accelerating, stepwise, etc.). We propose the generalized ”time warp” method for multi-component nonlinear motion estimation. It rewrites the D-TomoSAR system model to an M+1-dimensional standard spectral estimation problem, where M indicates the user defined motion model order and, hence, enables the motion estimation for all possible complex motion models. Experiments using TerraSAR-X spotlight data will be exemplified in which linear and periodic (seasonal) motion components can be separated and retrieved.

 

The abovementioned D-TomoSAR is based on long-term coherent pixels. For non-urban area, such pixels are usually scarce. Therefore, jointly exploiting distributed scatterer (DS) and persistent scatterer, known as SqueeSAR, will be explained. Experiments using TerraSAR-X high-resolution spotlight data shows that joint exploitation of DS and PS provides larger coverage by a factor of 1.5 to 20, depending on the region.

 

 

Biography

Xiaoxiang Zhu received the Master (M.Sc.) degree, her doctor of engineering (Dr.-Ing.) degree and Habilitation from Technical University of Munich (TUM), Germany, in 2008, 2011 and 2013, respectively. Since May 2011, she is a scientist with the Remote Sensing Technology Institute at the German Aerospace Center (DLR), Oberpfaffenhofen, where she is the head of the Team Signal Analysis and with the Chair of Remote Sensing Technology at TUM. Since September 2013, she is also a Helmholtz Young Investigator Group Leader. Her main research interests are: advanced InSAR techniques such as high dimensional tomographic SAR imaging and SqueeSAR; computer vision in remote sensing including object reconstruction and multi-dimensional data visualization; and modern signal processing, including innovative algorithms such as compressive sensing and sparse reconstruction, with applications in the field of remote sensing such as multi/hyperspectral image analysis. She is giving courses in signal processing, estimation theory and remote sensing. Dr. Zhu is the developer of the DLR's Tomographic SAR Processing System ─ Tomo-GENESIS. She is author of more than 80 scientific publications, among them 39 full-paper peer-reviewed papers and 6 paper awards.