ImageryOrthoimagery Helene 2025

<div style='text-align:Left;'><div><p><span>Product: These data were acquired by the NC Collaboratory at UNC Chapel Hill utilizing funds appropriated by the NC General Assembly. This orthoimagery data set includes 6 in digital orthoimages in GeoTIFF tiles and 32-bit 4-band (RGBIR).Geographic Extent: 13 counties in NorthCarolina, covering approximately 5,323 total square miles. Counties covered in their entirety for this project included: Alexander, Ashe, Watauga, Avery, Mitchell, Burke, Yancey, McDowell, Rutherford, Buncombe, Henderson, Haywood, and Jackson. Dataset Description: The Helene-North Carolina Priority 1 Lidar and Imagery project called for the planning, acquisition, and processing of imagery data to be collected at a ground sample distance (GSD) of 6 in. Project specifications are based on the American Society of Photogrammetry and Remote Sensing (ASPRS) standards. The data were developed based on a horizontal projection/datum of NAD 1983 2011 StatePlane North Carolina FIPS 3200 US Survey Foot. Imagery data were delivered as 6 in GeoTIFF tiles and 32-bit 4-band (RGBIR). Tiled deliverables contained 6,768 individual 5,000 ft x 5,000 ft tiles.Ground Conditions: Imagery was collected in spring 2025, and meets project acquisition parameters of being snow and ice free (though some light, undrifted snow may be present), no unusual flooding or water inundation, and leaf off conditions. The AECOM team established a total of 49 check points to assess the horizontal accuracy of the data, of which 39 were useable. The imagery data was post processed to meet task order specifications and was tested to meet ASPRS horizontal accuracy guidelines. Seamline editing and photoshop adjustments were focused on major transportation features due to the rapid response nature of the project and the need for damage analysis. Areas outside of major transportation features may exhibit seamline displacement and other anomalies such as smears.</span></p></div></div>

产品说明：本数据集由北卡罗来纳大学教堂山分校（University of North Carolina at Chapel Hill, UNC Chapel Hill）北卡罗来纳协作实验室（NC Collaboratory）使用北卡罗来纳州议会拨付的经费采集完成。该正射影像数据集包含6英寸地面采样距离的数字正射影像，以GeoTIFF瓦片格式存储，为32位4波段（RGBIR）影像。地理覆盖范围：涵盖北卡罗来纳州13个县，总面积约5323平方英里。本次项目完整覆盖的县包括：亚历山大县（Alexander）、阿什县（Ashe）、沃托加县（Watauga）、埃弗里县（Avery）、米切尔县（Mitchell）、伯克县（Burke）、扬西县（Yancey）、麦克道尔县（McDowell）、拉瑟福德县（Rutherford）、邦科姆县（Buncombe）、亨德森县（Henderson）、海伍德县（Haywood）以及杰克逊县（Jackson）。数据集描述：本数据集源自海伦-北卡罗来纳州优先级1激光雷达与影像项目（Helene-North Carolina Priority 1 Lidar and Imagery），该项目要求开展影像数据的规划、采集与处理，采集时的地面采样距离（Ground Sample Distance, GSD）为6英寸。项目规范遵循美国摄影测量与遥感学会（American Society of Photogrammetry and Remote Sensing, ASPRS）标准。数据集基于北美1983基准面2011版的北卡罗来纳州平面投影（FIPS 3200，美国测量英尺）构建。影像数据以GeoTIFF瓦片格式交付，为32位4波段（RGBIR）影像，地面采样距离为6英寸。分块交付成果共包含6768幅独立的5000英尺×5000英尺瓦片。采集环境：影像数据采集于2025年春季，符合项目采集参数要求：无积雪与积冰（或存在少量未堆积的薄雪）、无异常洪水或积水，且处于无叶状态。AECOM团队共设置49个检查点以评估数据集的水平精度，其中39个检查点有效。影像数据经过后处理以满足任务订单规范，并通过测试符合ASPRS水平精度指南。鉴于本项目的快速响应属性与灾害损伤分析需求，接缝线编辑与Photoshop调整主要针对主要交通设施开展。非主要交通设施区域可能存在接缝线位移及涂抹痕迹等异常情况。