CASSIE is an open-source web tool for automatic shoreline mapping and analysis using satellite imagery (www.cassiengine.com). This tool was built in JavaScript, using Google Earth Engine (GEE) API, and can be applied to any coastal region on Earth where a boundary between water and land exists. CASSIE use the Landsat and Sentinel-2 satellite imagery, freely available from GEE, and implements an automatic shoreline detection using the normalized difference water index (NDWI) together with Otsu image segmentation algorithm. The satellite-derived shorelines are analysed for a set of user-defined cross-shore transects along which several statistical analyses are performed. Comparisons of the CASSIE-derived shorelines and rate of changes with state-of-the art methods show that the products from this tool have sub-pixel accuracy. The new concept of big-data cloud-based computing and storage platform (GEE), together with a user-friendly interface and high level of automation makes of CASSIE a complete tool to support a wide variety of studies and applications where the knowledge of the shoreline behaviour is fundamental.

CASSIE是用于使用卫星图像进行自动海岸线地图绘制和分析的开源Web工具（www.cassiengine.com）。该工具是使用Google Earth Engine（GEE）API在JavaScript中构建的，可应用于地球上水陆之间存在边界的任何沿海地区。CASSIE使用GEE免费提供的Landsat和Sentinel-2卫星图像，并使用归一化差异水指数（NDWI）和Otsu图像分割算法实现自动海岸线检测。针对一组用户定义的跨岸样线分析了卫星派生的海岸线，并沿其执行了一些统计分析。使用CASSIE得出的海岸线和变化率与最新方法的比较表明，此工具的产品具有亚像素精度。