Quick Extraction Of Collapsed Buildings Due To The 2023 Turkey Earthquake From X-Band SAR Data

Two consecutive earthquakes with magnitudes exceeding 7 occurred in the Republic of Turkey on February 6, 2023, causing severe damage to cities along the causative fault lines. Many satellite images were provided soon after the earthquakes for supporting the emergency response. In this study, the authors conducted a quick extraction of collapsed individual buildings using two pre-event and one post-event TerraSAR-X intensity images. The differences of backscattering coefficients and the correlation coefficients were calculated for pre-event and co-event SAR data pairs. Collapsed buildings were then identified based on the thresholds defined by the pre-event pair. Compared with visual interpretation results from high-resolution optical images, 64% of the collapsed buildings were detected successfully, demonstrating the effectiveness of our proposed method at an early stage of disaster response.