HIGH-RESOLUTION SAR COHERENT CHANGE DETECTION IN URBAN ENVIRONMENT

• Published in: International archives of the photogrammetry, remote sensing and spatial information sciences. Vol. XLIII-B3-2020; pp. 1569 - 1575
• Main Authors: Manzoni, M., Monti-Guarnieri, A., Molinari, M. E.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Gottingen Copernicus GmbH 22.08.2020; Copernicus Publications
• Subjects: C band; Cadastral mapping; Change detection; Coherence; Constellations; Damage assessment; Detection; Disasters; Geographic information systems; Geographical information systems; High resolution; Information systems; Natural disasters; Post-production processing; Radar; Remote sensing; Resolution; SAR (radar); Sensitivity; Synthetic aperture radar; Urban areas; Urban development; Urban environments; Urbanization; Wavelength; Weather; Workflow
• ISSN: 2194-9034; 1682-1750; 2194-9034
• DOI: 10.5194/isprs-archives-XLIII-B3-2020-1569-2020

The identification of changes in urban settlements is of great interest for damage assessment after natural disasters, cadastral mapping and monitoring urban development and illegal activities.Radar-based remote sensing from space-borne platforms is quite useful in this scenario and Synthetic Aperture Radar (SAR) data is attractive due to its wide coverage, the day and night all-weather availability, and the sensitivity to slight changes in the scene structure. In this context, the launch of the European Space Agency (ESA) constellation Sentinel-1 has played a significant role: the exact repetition of the acquisition geometry, the repeated illumination and the sensitivity to centimetric changes thanks to the C-Band (5.4GHz) radar payload make Sentinel-1 the perfect instrument to monitor urban settlements.Coherent Change Detection (CCD) techniques are able to detect even the finest change in the structure of a target, so small to be comparable with the wavelength. This sensibility is an advantage, but turns into a drawback especially in an urban environment where every subtle change may cause an unwanted detection.This paper tackles the problem of the huge amount of triggered detections over urbanized areas with a combination of a high-resolution coherent multi-change detection technique and Geospatial Information System (GIS) post-processing. The final result is a map of buildings that are changed in the scene due to relevant variation of their structure. In this contribution, the complete workflow is explained, and a preliminary validation is carried out by means of a set of images gathered by Sentinel-1 and a set of optical images over the city of Manchester.