1.WGS84(4326)
影像 http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer
街道 http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer
地形 http://server.arcgisonline.com/arcgis/rest/services/NGS_Topo_US_2D/MapServer
2.WGS84 墨卡托 102100 (3857)
影像 http://server.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer
街道 http://server.arcgisonline.com/arcgis/rest/services/World_Street_Map/MapServer
地形 http://server.arcgisonline.com/arcgis/rest/services/World_Topo_Map/MapServer