Orthomosaic, digital surface model and point cloud of Edgeworth David Base Camp, Bunger Hills, 1st February 2025

Orthomosaic and Digital Surface Model of the Edgeworth David Camp during the de-establishment phase for Project 5219: Denman Terrestrial Campaign Operational Support 2023-2025. The data products were produced in Agisoft Metashape Professional (2.1.3 build 18946), using 1500 nadir photographs collected by a DJI Mavic 3E RTK drone with software DJI Pilot 2. The drone had a fixed connection to a DJI D-RTK2 base station that was established over an unknown point (established in position average mode). Drone photo positions (and exif metadata) is saved in the included geopackage. The orthomosaic was generated using 8 ground control points surveyed on the 01st of February using an Emlid Reach RS2+ base and rover pair, with the Emlid Reach base station established over survey mark NMS238 (input coordinates 100.603656 E 66.24993453 S, 4.177m ellipsoidal height). The resulting orthomosaic EDB_Feb_2025_orthomosaic_2.tif is in this data record. A secondary data product has also been produced, geo-referenced to the February 2023 orthomosaic using a 2nd order polynomial transformation and 12 control points (EDB_01_Feb_2025_orthomosaic_tied_Feb2025.tif, with control points saved in the file EDB_Feb_2025_orthomosaic_2.tif.points). Control points to tie the two orthomosaics were selected from recognisable inclusions and/or protrusions on prominent boulders, and are well distributed across the terrestrial part of the scene, but not on the epi-shelf ice, due to the lack of common features present at both time points. The orthomosaic represents a snapshot in time, as the Denman Terrestrial Campaign camp was being decommissioned. Some buildings have been removed, and at the time of image acquisition, a large amount of cargo for RTA was stored on the ice of the epi-shelf. 17 small tents (sleeping and ablutions) and 1 large mess tent are still erected. 4 red fibreglass ‘melon’ buildings, arranged around a prominent boulder, form the main Edgeworth David Base. At the time of acquisition, 2 melons and 2 apples from the Denman Terrestrial Campaign camp had been decommissioned, and the edges of the melon sites and the helicopter pad are marked by ropes.The point cloud was edited to remove obvious outliers, points with very low confidence (value equal to 1) and remove erroneous points from the centre of lake. The point cloud has not been classified, is in .las file format, and consists of 141,409,860 points. Project coordinate system is WGS 84 / UTM Zone 47S (EPSG::32747). Project positioning errors calculated by Agisoft Metashape from the 8 ground control points are 3.5 and 3.7 cm in X and Y, and 21.2 cm in Z dimension (RMSE). DEM is in height above ellipsoid. This dataset is part of a time series. Another mapping mission was conducted 3 days after this one.See also metadata records for preceding time points:22 December 2022 http://dx.doi.org/doi:10.26179/cc4z-h403 06 February 2023 http://dx.doi.org/doi:10.26179/146h-9b03

本数据集为5219号项目：2023-2025年登曼陆地行动支援项目撤营阶段的埃奇沃思·戴维营地（Edgeworth David Camp）正射镶嵌图（Orthomosaic）与数字表面模型（Digital Surface Model, DSM）。本数据产品采用DJI Mavic 3E RTK无人机搭载DJI Pilot 2软件采集的1500张天底角照片，通过Agisoft Metashape Professional（2.1.3 build 18946）生成。该无人机与DJI D-RTK2基准站保持固定连接，基准站架设于未知点位并采用位置平均模式进行解算。无人机照片的位置信息（及EXIF元数据）存储于附带的GeoPackage文件中。本次正射镶嵌图通过8个地面控制点（Ground Control Point, GCP）生成，控制点于2月1日采用Emlid Reach RS2+基准站与流动站组合进行外业测量，Emlid Reach基准站架设于测量标记NMS238之上，其输入坐标为东经100.603656、南纬66.24993453，椭球高4.177米。本数据记录中包含生成的正射镶嵌图文件EDB_Feb_2025_orthomosaic_2.tif。此外本数据集还生成了次级数据产品：通过二阶多项式变换与12个同名控制点，将2025年2月的正射镶嵌图配准至2023年2月的正射镶嵌图，对应文件为EDB_01_Feb_2025_orthomosaic_tied_Feb2025.tif，同名控制点存储于文件EDB_Feb_2025_orthomosaic_2.tif.points中。用于配准两幅正射镶嵌图的控制点选自显著岩块上可识别的凸起或凹陷特征，其在测区的陆地区域分布均匀，但未选取冰架表层冰（epi-shelf ice）上的点位，原因是两个时相的冰架表层冰缺乏共通特征。该正射镶嵌图为登曼陆地行动营地撤营阶段的瞬时快照。部分建筑已被拆除，图像采集时，大量RTA物资被存放于冰架表层冰面上。营地内仍保留17顶小型帐篷（用于住宿与洗漱）及1顶大型食堂帐篷。4座红色玻璃钢‘瓜形’建筑围绕一块显著岩块排布，构成埃奇沃思·戴维主基地。图像采集时，登曼陆地行动营地的2座瓜形建筑与2座‘苹果形’建筑已完成撤收，瓜形建筑旧址与直升机坪的边缘以绳索标识。点云数据已进行编辑处理，剔除了明显的离群点、置信度极低（值为1）的点，并移除了湖泊中心的错误点云。该点云未进行分类，存储为LAS格式文件，共包含141,409,860个点。本项目采用的坐标系为WGS 84 / UTM 47S带南幅（EPSG::32747）。Agisoft Metashape基于8个地面控制点计算得到的项目定位误差：X方向为3.5厘米，Y方向为3.7厘米，Z方向为21.2厘米（均方根误差，Root Mean Square Error, RMSE）。数字高程模型（Digital Elevation Model, DEM）采用椭球高作为高程基准。本数据集属于时间序列数据集的一部分，本次测绘任务结束3天后还开展了另一项测绘任务。此外可查阅此前时相的元数据记录：2022年12月22日，DOI:10.26179/cc4z-h403；2023年2月6日，DOI:10.26179/146h-9b03。