PS X (Chapter II, Evans Dissertation)

This is drone product set X from Chapter II of Alexandra's dissertation.<br>The orthomosaic and DSM show the Pawcatuck Bradford fishway area in Bradford, RI, USA. The imagery was collected on July 24, 2019 using a DJI Phantom 3 Professional drone. Note that the elevation values are only reliable for examining relative topography across the site. The built-in drone GPS was used for georeferencing during SfM processing, and the EXIF data provided inaccurate altitude measurements. The XY locations are more reliable based on checks against alignment with base maps in ArcGIS. The drone PS' relative accuracy was deemed acceptable for the purposes in Chapter II. Automated drone flight paths were used to collect nadir and angled aerial images with sufficient image overlap for SfM processing in Agisoft PhotoScan Professional. The PhotoScan-generated report includes additional details on the SfM processing workflow and on the drone products.<br>Please see Alexandra's dissertation (University of New Hampshire) for more information on the drone products and project.<br>These materials were made using resources from an NSF EPSCoR funded project “RII Track-2 FEC: Strengthening the scientific basis for decision-making about dams: Multi-scale, coupled-systems research on ecological, social, and economic trade-offs” (a.k.a. "Future of Dams"). Support for this project is provided by the National Science Foundation’s Research Infrastructure Improvement NSF #IIA-1539071. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

本数据集为亚历山德拉（Alexandra）学位论文第二章中的无人机产品集X。该正射影像镶嵌图（orthomosaic）与数字表面模型（DSM）展示了美国罗德岛州布拉德福德市的波卡特克-布拉德福德鱼道区域。本次影像采集于2019年7月24日，搭载设备为大疆（DJI）精灵3专业版（Phantom 3 Professional）无人机。
请注意，仅在分析该区域的相对地形时，高程数值方具备可靠性。在运动恢复结构（Structure from Motion，SfM）处理流程中，采用无人机内置GPS进行地理配准，但可交换图像文件格式（Exchangeable Image File Format，EXIF）元数据提供的高程测量值存在误差。经与ArcGIS地理信息系统底图比对验证后，该数据集的XY坐标位置可信度更高。本项目第二章的研究目标对无人机测绘产品的相对精度要求，经评估已符合可接受标准。
本次影像采集采用自动化无人机飞行航线，获取了垂直天底方向与倾斜角度的航空影像，影像重叠度满足Agisoft PhotoScan专业版的SfM处理要求。由PhotoScan生成的处理报告中，包含了SfM处理流程与无人机产品的更多细节信息。
如需了解该无人机产品与项目的更多细节，请参阅亚历山德拉于新罕布什尔大学（University of New Hampshire）提交的学位论文。
本项目由美国国家科学基金会（National Science Foundation, NSF）EPSCoR计划资助，项目全称"RII Track-2 FEC: Strengthening the scientific basis for decision-making about dams: Multi-scale, coupled-systems research on ecological, social, and economic trade-offs"（别称"Future of Dams"，即"大坝的未来"）。本项目同时获得美国国家科学基金会科研基础设施改进项目（NSF #IIA-1539071）的资助。本材料中表达的任何观点、研究结果、结论或建议仅代表作者本人，并不一定代表美国国家科学基金会的官方立场。