Maine Orthoimagery Regional 1 Foot 2003 to 2005 (Imagery Layer)

Image Service | OGC WCS | OGC WMS | KMZ ORTHO_1F are high resolution digital orthophotographs produced from aerial photos collected over southwestern, central and northeastern Maine in the Spring of 2003, 2004 and 2005. Each pixel represents a planimetric square 1 foot on a side on the ground. Aerial photography for ORTHO_1F was flown at 6,000 feet above mean ground level. Source elevation data were 10 meter Digital Elevation Models produced for this project by USGS from 1:24,000 scale elevation and hydrography data supplied by MEGIS. The digital orthorectified images (image chips) are referenced to North American Datum 1983, UTM Zone 19, expressed in units of meters. Cartographic Services for orthorectification and the creation of digital elevation models were provided by USGS Mid-Continent Mapping Center (USGSMCMC). ORTHO_1F provides a digital photographic map suitable for applications requiring a 1:2400 map scale, a National Map Accuracy Standard (NMAS) of +/- 6.67 feet. The multi-agreement program was developed and funded in coordination with the Maine GeoLibrary Board. The U.S. Department of Agriculture, Natural Resource Conservation Service (NRCS) contributed toward this project via a separate funding agreement with USGS. The completed orthorectified files represent quarter-quarter-quadrangle (QQQ) sized tiles with a 300m over-edge. All overedges for ORTHO_1F also overlap adjacent ORTHO_HF and ORTHO_2F orthophotography by this distance. ORTHO_1F tiles provide complete coverage of the TIER A boundaries as defined by the Towns designated TIER A will have complete coverage by 1 foot GSD imagery.影像服务 | 开放地理空间联盟Web覆盖服务（OGC WCS） | 开放地理空间联盟Web地图服务（OGC WMS） | KMZ格式ORTHO_1F，是2003、2004及2005年春季于美国缅因州西南部、中部与东北部空域采集航空影像后制作的高分辨率数字正射影像。每个像素对应地面上边长1英尺的平面正方形区域。ORTHO_1F的航空摄影作业飞行高度为平均地面海拔以上6000英尺。本项目的源高程数据为10米分辨率数字高程模型（Digital Elevation Models），由美国地质调查局（USGS）基于缅因州地理信息服务中心（MEGIS）提供的1:24000比例尺高程与水文数据制作完成。该数字正射影像（影像切片）采用1983北美大地基准面、通用横轴墨卡托投影第19带（UTM Zone 19）坐标系，坐标单位为米。正射校正与数字高程模型制作的制图服务，由美国地质调查局中大陆制图中心（USGS Mid-Continent Mapping Center, USGSMCMC）提供。ORTHO_1F可适配1:2400比例尺地图的相关应用需求，满足国家地图精度标准（National Map Accuracy Standard, NMAS）±6.67英尺的精度要求。本多机构协作项目由缅因地理图书馆委员会（Maine GeoLibrary Board）协调开展并提供资金支持，美国农业部自然资源保护局（Natural Resource Conservation Service, NRCS）通过与USGS签订的单独资助协议为本项目提供经费。已完成的正射影像文件为四分之一四分之一图幅（quarter-quarter-quadrangle, QQQ）尺寸的瓦片，带有300米的图幅重叠边。所有ORTHO_1F的重叠边均以此距离与相邻的ORTHO_HF、ORTHO_2F正射影像产生重叠。ORTHO_1F瓦片完整覆盖了A级边界范围，即被划定为A级的城镇将获得1英尺地面采样距离（Ground Sample Distance, GSD）影像的全覆盖服务。