Heard and McDonald Islands data collated early 1998 GIS Dataset

This layer is stored as two datasets (point and polygon)in the Geographical Information System (GIS). Points represent landing areas, mammal, flying bird and penguin data. Polygons represent the horizontal flight limits of helicopters and areas set aside for specific management purposes.该图层在地理信息系统（Geographical Information System，GIS）中以点数据集与多边形数据集两种形式存储。其中，点数据集对应着陆区域、哺乳动物、飞行鸟类及企鹅的相关数据；多边形数据集则代表直升机的水平飞行限制范围，以及为特定管理用途划定的专属区域。