Disaster damage assessment asks which assets, infrastructure, land areas, or communities were damaged after an event and how severe that damage appears from remotely sensed evidence. Copernicus EMS Mapping uses satellite imagery and other geospatial data for natural and human-made disasters, including rapid mapping for emergency response and damage assessment of infrastructure.^[1]

The EO output is a proxy, not ground truth. Copernicus EMS states that satellite-based damage assessment is limited by bird's-eye viewing geometry, image resolution, radiometry, and interpretation subjectivity; its rapid damage classes are adapted for what can be seen from space or airborne imagery.^[2] In rush mode, Copernicus grading maps assess disaster damage extent, type, and damage grades for affected assets.^[3]

Methodologically, established routes include before/after change detection, SAR backscatter change, SAR coherent change detection, and supervised classification where training labels and consistent pre/post imagery exist. Very-high-resolution optical imagery can provide fine visual context for structural damage and burn scars, while the analytical method remains before/after optical change interpretation. SAR supports flood and cloud-obscured events; optical change detection supports visible structural damage, burn scars, and other pre/post surface changes.