Ph.D. in Information Technology: Final Dissertations
DEIB - Alfa Room (ground floor, via Golgi 40, Milano)
June 27th, 2016
2.00 pm
June 27th, 2016
2.00 pm
Abstract
On June 27th, 2016 the final dissertations of the candidates of the Ph.D. in Information Technology will be held at DEIB Alfa Room and will start at 2.00 pm:
Simone Mancon – XXVIII Cycle
"Geometric Parameters Retrieval in SAR Systems"
Advisor: Prof. Andrea Virgilio Monti Guarnieri
Abstract:
The objective of this research is the analysis of the effects of the geometrical error on the SAR data, focusing on the SAR applications that consider the differences between SAR acquisitions of the same scene. In order to do this the dissertation provides a theoretical model by defining the relationship between the difference of the target positioning in two SAR acquisitions and the error of the nominal with respect the actual geometry. The mathematical formulation is applicable both to interferometric and non-interferometric acquisitions; considering that the positioning difference can be mea- sured either as Interferometric (InSAR) phase or as mis-registration shift according to the applications. The analysis of the theoretical model allows to evaluate which components of the geometrical error can be estimated for different configurations of the SAR system, and the theoretical accuracy achievable. All the analyses included in this thesis mainly deal with spaceborne SAR applications.
The first part of the dissertation is devoted to the derivation of the theoretical model of the geometrical errors and its verification with simulated data. In particular, this part defines a mathematical formulation of the effects of the geometrical errors on the misregistration shift in Line-Of-Sight (LOS) and Along-Track (AT) directions in case of interferometric acquisitions. Concerning the non-interferometric case, the LOS misregistration only will be dealt with. At the end of this part, the InSAR phase contributions due to the Atmospheric Phase Screen (APS) and the target displacement will be analyzed in order to investigate their impact on the geometric parameters retrieval.
Two different SAR applications that exploit the suggested theoretical model will be described in the second part of the thesis. The first application uses the AT misregistration, in the field of the interferometric calibration, to validate the accuracy of the orbit products. As a case study, the results of the orbit error retrieval will be shown for the Sentinel-1 satellite with a particular attention to the TopSAR acquisition mode. Finally, the second application exploits the theoretical model in order to estimate the Digital Elevation Model (DEM) error by using non-interferometric acquisitions. In particular, the reported case study refines the SRTM DEM by an iterative radargrammetric technique applied to high resolution SAR images in X-band. The radargrammetric DEM generated by the suggested technique will be then compared to a photogrammetric DEM available for the area.
Marco Savi – XXVIII Cycle
"Overcoming performance, cost and energy issues in Fixed and Mobile Convergent networks"
Advisor: Prof. Giacomo Verticale
Abstract:
Internet traffic is exploding by following an exponential growth. The telecommunication operators are struggling to face such unprecedented phenomenon. The telecommunication networks, especially the access and aggregation networks, need to evolve, and the research community is working hard to develop novel technical solutions that can help in mitigating the performance, cost and energy issues caused by such traffic growth.
In this thesis we focus on three of the most promising technologies to achieve this goal: Fixed and Mobile Convergence (FMC), Distributed Content Delivery and Network Function Virtualization (NFV).
We investigate benefits and technical challenges arising by their adoption in the access and aggregation segments of the network. We especially show that a joint adoption of FMC, Distributed Content Delivery and NFV principles can consistently help in reducing costs and energy consumption without significantly affecting performance.
Simone Mancon – XXVIII Cycle
"Geometric Parameters Retrieval in SAR Systems"
Advisor: Prof. Andrea Virgilio Monti Guarnieri
Abstract:
The objective of this research is the analysis of the effects of the geometrical error on the SAR data, focusing on the SAR applications that consider the differences between SAR acquisitions of the same scene. In order to do this the dissertation provides a theoretical model by defining the relationship between the difference of the target positioning in two SAR acquisitions and the error of the nominal with respect the actual geometry. The mathematical formulation is applicable both to interferometric and non-interferometric acquisitions; considering that the positioning difference can be mea- sured either as Interferometric (InSAR) phase or as mis-registration shift according to the applications. The analysis of the theoretical model allows to evaluate which components of the geometrical error can be estimated for different configurations of the SAR system, and the theoretical accuracy achievable. All the analyses included in this thesis mainly deal with spaceborne SAR applications.
The first part of the dissertation is devoted to the derivation of the theoretical model of the geometrical errors and its verification with simulated data. In particular, this part defines a mathematical formulation of the effects of the geometrical errors on the misregistration shift in Line-Of-Sight (LOS) and Along-Track (AT) directions in case of interferometric acquisitions. Concerning the non-interferometric case, the LOS misregistration only will be dealt with. At the end of this part, the InSAR phase contributions due to the Atmospheric Phase Screen (APS) and the target displacement will be analyzed in order to investigate their impact on the geometric parameters retrieval.
Two different SAR applications that exploit the suggested theoretical model will be described in the second part of the thesis. The first application uses the AT misregistration, in the field of the interferometric calibration, to validate the accuracy of the orbit products. As a case study, the results of the orbit error retrieval will be shown for the Sentinel-1 satellite with a particular attention to the TopSAR acquisition mode. Finally, the second application exploits the theoretical model in order to estimate the Digital Elevation Model (DEM) error by using non-interferometric acquisitions. In particular, the reported case study refines the SRTM DEM by an iterative radargrammetric technique applied to high resolution SAR images in X-band. The radargrammetric DEM generated by the suggested technique will be then compared to a photogrammetric DEM available for the area.
Marco Savi – XXVIII Cycle
"Overcoming performance, cost and energy issues in Fixed and Mobile Convergent networks"
Advisor: Prof. Giacomo Verticale
Abstract:
Internet traffic is exploding by following an exponential growth. The telecommunication operators are struggling to face such unprecedented phenomenon. The telecommunication networks, especially the access and aggregation networks, need to evolve, and the research community is working hard to develop novel technical solutions that can help in mitigating the performance, cost and energy issues caused by such traffic growth.
In this thesis we focus on three of the most promising technologies to achieve this goal: Fixed and Mobile Convergence (FMC), Distributed Content Delivery and Network Function Virtualization (NFV).
We investigate benefits and technical challenges arising by their adoption in the access and aggregation segments of the network. We especially show that a joint adoption of FMC, Distributed Content Delivery and NFV principles can consistently help in reducing costs and energy consumption without significantly affecting performance.