Maine Orthoimagery Municipal Gorham 2022

Maine Statewide Orthoimagery Project - During the spring of 2020 new 4-band (R, G, B, and NIR) aerial imagery was acquired covering the entire project area using Leica ADS digital camera systems. All imagery was collected during the 2022 spring flying season during leaf-off conditions for deciduous vegetation in the State of Maine. The sun angle shall be 25-degrees or greater, and streams should be within their normal banks, unless otherwise negotiated. During flight planning and acquisition, a significant effort is made to limit clouds, snow (please note: small amounts of snow such as piles in parking lots, extreme shaded areas, within dense evergreens or unpopulated northern facing slopes may be acceptable), fog, haze, smoke, or other ground obscuring conditions in the imagery. In no case will the maximum cloud cover exceed 5% per image. Within the immediate areas of power plants, factories, or controlled agricultural burns some steam or smoke and/or shadows may be visible on imagery. Woolpert produced new 8-bit, 4-band stacked color digital orthoimagery files in GeoTIFF format with TFW “world file” at a 45cm (18-inch), 30cm (12-inch), 15cm (6-inch) and 7.5cm (3-inch). The Maine GeoLibrary Board has developed a statewide, 5-year, rotating orthoimagery acquisition program for Maine to facilitate state, regional and local government GIS base mapping in an efficient and cost-effective program. The State of Maine will use digital orthoimagery for the development of various base map products in a computerized GIS that will support the needs of the state and multiple stakeholders through applications, such as, multi-jurisdictional homeland security mapping applications, state and county emergency management applications, regional and local planning, state and local public safety applications, economic development and other GIS business objectives.缅因州全州正射影像项目（Maine Statewide Orthoimagery Project）：2020年春季，项目团队使用徕卡ADS（Leica ADS）数码相机系统，采集了覆盖整个项目区域的新型4波段（红（R）、绿（G）、蓝（B）及近红外（Near Infrared，缩写NIR））航空影像。所有影像均于2022年春季飞行季，在缅因州落叶植被落叶期完成采集。采集要求太阳高度角不低于25度，且溪流需处于正常岸线范围内，另有约定的情况除外。在飞行规划与影像采集阶段，项目团队将尽力管控影像中的云、雪（请注意：停车场积雪堆、极端阴影区域、茂密常绿林内或无人居住北坡等少量积雪可被接受）、雾、霾、烟雾及其他遮挡地面的干扰因素。单幅影像的最大云量占比严禁超过5%。在发电厂、工厂或受控农业焚烧的紧邻区域内，影像中可能出现少量蒸汽、烟雾或阴影。Woolpert生成了规格为8位的4波段堆叠式彩色数字正射影像（orthoimagery）文件，格式采用GeoTIFF，附带TFW "世界文件（world file）"，分辨率涵盖45cm（18英寸）、30cm（12英寸）、15cm（6英寸）及7.5cm（3英寸）。缅因州地理图书馆委员会（Maine GeoLibrary Board）为缅因州制定了一项为期5年的全州轮换式正射影像采集计划，旨在以高效且经济的方式，支撑州、区域及地方政府的地理信息系统（Geographic Information System，缩写GIS）基础制图工作。缅因州将利用该数字正射影像开发计算机化GIS中的多款基础地图产品，通过各类应用场景满足州政府及多方利益相关方的需求，应用场景包括跨辖区国土安全制图、州及县级应急管理、区域与地方规划、州及地方公共安全、经济发展及其他GIS业务目标相关工作。