Medium resolution vector polylines of the Antarctic coastline

Dataset compiled from a variety of Antarctic map and satellite image sources. The dataset was created using ArcGIS and QGIS GIS software programmes and has been checked for basic topography and geometry checks, but does not contain strict topology. Quality varies across the dataset and certain areas where high resolution source data were available are suitable for large scale maps whereas other areas are only suitable for smaller scales. Each line has attributes detailing the source which can give the user further indications of its suitability for specific uses. Attributes also give information including 'surface' (e.g. grounding line, ice coastline, ice shelf front) and revision date. Compiled from sources ranging in time from 1990s-2020 - individual lines contain exact source dates. This medium resolution version has been generalised from the high resolution version. All areas inferior to 0.1km² not intersecting anything else were deleted and the 'simplify' tool was used in ArcGIS with the 'point remove' algorithm and a smoothing tolerance of 50 m.本数据集整合自多份南极地图与卫星影像数据源。本数据集依托ArcGIS与QGIS两款地理信息系统（GIS）软件构建完成，已完成基础地形与几何校验，但未包含严格拓扑结构。数据集整体质量存在差异：部分区域拥有高分辨率源数据，可用于制作大比例尺地图；其余区域仅适配小比例尺地图制作。每条线要素均附带详细的数据源属性信息，可为用户判断其适配的具体应用场景提供参考。属性信息还包含‘地表类型’（例如冰盖接地线、冰海岸线、冰架前缘）与修订日期等内容。数据源的时间跨度覆盖1990年代至2020年，每条线要素均标注了精确的源数据获取日期。本中分辨率版本由高分辨率版本泛化而来：已删除所有面积小于0.1平方千米且未与其他要素相交的区域，并在ArcGIS中使用点移除算法与50米的平滑容差调用了简化工具。