Tomographic SAR Reconstruction of a 4D City using TerraSAR-X data

Inhaltsverzeichnis (Table of Contents)

• Introduction
• Motivation: The 4th Dimension
• Purpose and Structure
• About TerraSAR-X
• TerraSAR-X Scanning Modes
• Theoretical Basics - SAR Principles
• SAR Geometry
• SAR Phase
• SAR Properties
• Layover
• Chirp
• Speckle
• SAR Image Resolution
• InSAR Basics
• Interferometric Phase
• InSAR Athmospheric Influences
• InSAR Height Retrieval
• Persistent Scatterer Interferometry (PSI)
• SAR Tomography
• TomoSAR
• TomoSAR Processing Procedures
• Pre-Processing
• Processing
• TomoSAR System Model
• TomoSAR Algorithm
• Application on Berlin Data Stack
• Downsampling
• Quality Measurements
• Creating Pixel Pairs
• Integration
• Filter Residual Phase
• Upsamling and Estimation
• Results and Analysis
• Deformations and Movements
• Seasonal Movements
• Linear Movements
• Verification and Observation of the processed SAR Data Stack
• TomoSAR Result Observation
• Virtual Inspection of Observation
• Inspected Targets
• ”Uberflieger Br¨ ¨ ucke”
• ”Berlin Hauptbahnhof”
• Conclusion

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

The main objective of this bachelor thesis is to analyze the ground movements of an urban area using SAR images and TomoSAR techniques. The goal is to monitor urban infrastructure movements to prevent potential collapses using satellite images, which allows for a larger surveillance area compared to conventional ground geodesy measurements. The area of interest is the area around the Berlin main station and the Berlin zoo.

• The application of SAR Tomography for 4D city modeling.
• The use of very high resolution (VHR) SAR data for urban infrastructure monitoring.
• The identification and analysis of ground movements and building deformations in urban areas.
• The comparison of TomoSAR results with existing 3D city models.
• The potential and limitations of TomoSAR for future geodetic observations.

Zusammenfassung der Kapitel (Chapter Summaries)

The first two chapters focus on the theoretical basics of SAR and TomoSAR. Chapter 2 covers the principles of SAR, including SAR geometry, phase, properties like layover, chirp and speckle, as well as the resolution of SAR images. It also introduces InSAR basics, including interferometric phase, atmospheric influences, and height retrieval. Finally, it delves into Persistent Scatterer Interferometry (PSI) and SAR Tomography.

Chapter 3 then explores TomoSAR in more detail, including the processing procedures, pre-processing techniques to eliminate atmospheric phase screen (APS), and the different algorithms used for tomographic reconstruction. It describes the system model and the two primary TomoSAR algorithms, Maximum Detection and SLIMMER.

Chapter 4 delves into the application of TomoSAR on a high resolution TerraSAR-X data stack of Berlin. It outlines the steps taken for data pre-processing, including downsampling, quality measurements, creating pixel pairs, integration, filtering the residual phase, and upsampling and estimation.

Finally, Chapter 5 presents the results and analysis of the TomoSAR processing. It discusses the detected ground movements and building deformations, including seasonal and linear movements, and verifies the results by comparing them to real-world data and existing 3D city models.

Schlüsselwörter (Keywords)

The thesis focuses on the application of SAR Tomography (TomoSAR) for monitoring urban infrastructure movements. Key topics include very high resolution (VHR) SAR data, TerraSAR-X satellite data, 4D city modeling, ground deformation, and atmospheric phase screen (APS) elimination. It also explores the comparison of TomoSAR results with real-world data and existing 3D city models.