Reference Grids USGS Quad

This dataset contains a reference grid for the state of Alaska. This map indices contained in this layer are divided into 15' of latitude. The source dataset is in the State Plane projected coordinate system NAD 1983 StatePlane Alaska 4 FIPS 5004 (US Feet).本数据集涵盖阿拉斯加州的参考格网（reference grid）。该图层所包含的地图索引按纬度15分进行划分。源数据集采用州平面投影坐标系（State Plane projected coordinate system），具体为北美1983基准面阿拉斯加4区联邦信息处理标准5004（美制英尺，US Feet）。