Maine Orthoimagery Municipal Houlton 2022

Maine Statewide Orthoimagery Project - During the spring of 2022 the Woolpert team acquired new 4-band (R, G, B, and NIR). The imagery was acquired covering the entire project area using UltraCam Eagle 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 7.5cm (3-inch) and 15cm (6-inch).缅因州全州正射影像项目（Maine Statewide Orthoimagery Project）——2022年春季，Woolpert团队采用UltraCam Eagle（UltraCam Eagle）数码相机系统，采集了覆盖整个项目区域的全新4波段（红、绿、蓝及近红外）影像数据。所有影像均采集于2022年春季飞行季，彼时缅因州的落叶植被处于落叶期。飞行时需保证太阳高度角不低于25度，且溪流需处于正常水位岸线范围内，另有约定的情况除外。在飞行规划与影像采集过程中，项目团队将尽最大努力限制影像中出现云、雪（注：停车场积雪堆、极端阴影区域、茂密常绿植被内或人口稀少的北向坡面等少量积雪可接受）、雾、霾、烟雾或其他地面遮挡物。单张影像的最大云量占比不得超过5%。在发电厂、工厂或受控农业焚烧的紧邻区域内，影像中可能会出现少量蒸汽、烟雾及/或阴影，此情况可接受。Woolpert团队产出了8位深度、4波段堆叠式彩色数字正射影像文件，格式为GeoTIFF（GeoTIFF），附带TFW"世界文件"，空间分辨率分别为7.5厘米（3英寸）与15厘米（6英寸）。