Snow Cover Mapping and Ice Avalanche Monitoring From the Satellite Data of the Sentinels

Abstract

ABSTRACT:In order to monitor ice avalanches efficiently under disaster emergency conditions, a snow cover mapping method based on the satellite data of the Sentinels is proposed, in which the coherence and backscattering coefficient image of Synthetic Aperture Radar (SAR) data (Sentinel-1) is combined with the atmospheric correction result of multispectral data (Sentinel-2). The coherence image of the Sentinel-1 data could be segmented by a certain threshold to map snow cover, with the water bodies extracted from the backscattering coefficient image and removed from the coherence segment result. A snow confidence map from Sentinel-2 was used to map the snow cover, in which the confidence values of the snow cover were relatively high. The method can make full use of the acquired SAR image and multispectral image under emergency conditions, and the application potential of Sentinel data in the field of snow cover mapping is exploited. The monitoring frequency can be ensured because the areas obscured by thick clouds are remedied in the monitoring results. The Kappa coefficient of the monitoring results is 0.946, and the data processing time is less than 2 h, which meet the requirements of disaster emergency monitoring.

On the Use of Interferometric Synthetic Aperture Radar Data for Monitoring and Forecasting Natural Hazards

“…Flood data are analyzed, for example, in Kussul et al (2008), Pulvirenti et al (2011), Stephens et al (2012, and Vishnu et al (2019), where a segmentation of the amplitude component of SAR images is performed in order to assess flood extent. Other examples concerning monitoring of avalanches are Eckerstorfer and Malnes (2015) and Wang et al (2018), where avalanche are detected using the amplitude component of SAR images. The reader may also refer to Eckerstorfer et al (2016) for a review on remote sensing for avalanche detection using optical, LiDAR, and radar sensors.…”