Remote sensing: Feasibility of change/damage detection in urban areas and structures by synthetic aperture radar (SAR) imagery

This dissertation studies the feasibility of change and damage detection in urban environments using the Synthetic Aperture Radar (SAR) imaging technology. SAR is an active sensor and capable to provide high-resolution images in all weather and all time conditions. It shows promise for acquiring spatial and temporal data for urban analysis and damage assessment after a disastrous event such as an earthquake. This technology can be used to diagnose the levels of regional damage and can be beneficial in emergency management operations to assess the level of losses and for prioritizing the rescue efforts in the affected areas.; The objective of this study is threefold, First, the mathematical theory and physical background of SAR data acquisition and processing are described and introduced. Second, a simulation tool based on the electromagnetic wave formulation is used to simulate SAR images of real-sized buildings and Radar Cross Section (RCS) of the dominant urban features as a proof of concept to demonstrate the usefulness of SAR applications and its imaging potentials and characteristics relevant to urban areas. The simulation results of the buildings and their associated hypothetical geometrical changes proved clearly that structural level changes can be detected. Finally, this report explores different techniques of change and damage detection using SAR satellite data for the case of Marmara earthquake.; Marmara earthquake devastated Turkey on August 17, 1999. Different modes of structural failure were observed in the region, ERS SAR data (for before and after earthquake) are used in here. Image processing and change detection algorithms are applied to before and after SAR complex images. SAR image comparison, SAR correlation, coherence and cross-power maps show valuable means for change detection and can sense the location of building damages. SAR interferometry is also implemented and discussed. To develop the damage maps, remote sensing and Geographic Information Systems (GIS) are integrated for the analysis, data management and displaying the results.