英文含义
DOQQ的全称：Digital Orthophoto Quarter-Quadrangle (1:12,000 scale representations of a quarter of the area of a conventional USGS 7.5 minute topographical map produced using aerial photographs) | 中文意思：───数字正射影像季度四合院(1:12,000代表的传统USGS 7.5分钟使用空中拍摄的照片产生地形图领域的季度)