Grey Scale Basemap Layers

These are the basemap layers that contain all of the MIT light grey basemap layers used for thematic mapping. These updated layers were published from the newly formatted MIT Basemap database (2025)本数据集包含全部用于专题制图的麻省理工学院（MIT）浅灰色底图图层。本次更新的图层源自2025年全新格式化的MIT底图数据库并正式发布。