Landslide Mapping Using SAR Imagery with Precise Registration

Since synthetic-aperture radar (SAR) imagery is not susceptible to weather and sunlight conditions, it is suitable for disaster mapping. However, ionospheric refraction of microwaves influence the registration of SAR imagery and reduces mapping accuracy, consequently hindering quick rescue operations. In this work, a registration method based on phase correlation was applied for SAR intensity images to map landslides caused by heavy rain in Japan. The mapping accuracy improved by decreasing false positives via co-registration. A specific pattern of intensity changes was observed around collapses, which is attributable to topographic changes due to landslides. The pattern reduced false positives further when used in pattern matching.