Drone photogrammetric orthomosaic, digital surface model and point cloud of Robinson Ridge, February 2022

This dataset includes a 17 hectare orthomosaic, digital surface model, and derived raster layers from Robinson Ridge, Windmill Islands, East Antarctica. The area captured includes the vegetation quadrats used to monitor vegetation health as part of the State of the Environment Indicator 72: Windmill Islands terrestrial vegetation dynamics (Robinson, 2009). It also covers the location of the 300m long soil biodiversity transect initially sampled in 2005 as part of Australian Antarctic Science Project 2952 (Spatial variability in polar soil ecosystems) and sampled again in 2019 as part of Australian Antarctic Science Project 4406.The orthomosaic is compiled from 666 downward-facing (nadir) photographs obtained with a DJI Matrice 300 RTK drone and Zenmuse P1 (35 mm) RGB sensor, on 01/02/2022. These images were processed using the ESRI SiteScan software (Pix4DengineSDK v5.0.45) to produce a 19.3-hectare-digital surface model (DSM) and orthomosaic with an average ground sampling distance (GSD) of 1.02 cm. The estimated root mean square (RMS) error of the seven ground control points (GCPs) was 7 cm. A digital terrain model was also produced, with a GSD of 5.1 cm. In order to produce the hydrological network (flow accumulation), the 1 cm DSM was downsampled to 10 cm resolution using QGIS 3.26.3 ‘Buenos Aires’. SAGA v7.8.2 (64 bit) was used to fill sinks and run a flow accumulation model using the Kinematic Routing Algorithm, and a threshold was applied to produce a ‘stream network’.

本数据集包含来自东南极洲（East Antarctica）风车群岛（Windmill Islands）罗宾逊岭（Robinson Ridge）的17公顷正射影像镶嵌图（orthomosaic）、数字表面模型（digital surface model, DSM）及衍生栅格图层（raster layers）。本次采集覆盖的区域包含作为《环境状况指标72：风车群岛陆地植被动态》（State of the Environment Indicator 72，Robinson, 2009）中监测植被健康所用的植被样方（vegetation quadrats）。该区域同时涵盖了2005年作为澳大利亚南极科学项目2952（极地土壤生态系统空间变异）的组成部分首次采样的300米长土壤生物多样性样带（soil biodiversity transect）点位，并于2019年作为澳大利亚南极科学项目4406的一部分再次开展采样。该正射影像镶嵌图由2022年2月1日使用大疆Matrice 300 RTK无人机（DJI Matrice 300 RTK drone）搭载禅思P1（35mm）RGB传感器（Zenmuse P1 (35 mm) RGB sensor）拍摄的666张下视（天底点）照片合成。采用ESRI SiteScan软件（Pix4DengineSDK v5.0.45）对上述影像进行处理，生成19.3公顷的DSM与正射影像镶嵌图，其平均地面采样距离（ground sampling distance, GSD）为1.02厘米。7个地面控制点（ground control points, GCPs）的估算均方根误差（root mean square, RMS）为7厘米。同时生成了地面采样距离为5.1厘米的数字地形模型。为生成水文网络（hydrological network）与流量累积（flow accumulation）结果，采用QGIS 3.26.3“布宜诺斯艾利斯”版本将1厘米分辨率的DSM降采样至10厘米分辨率。使用SAGA v7.8.2（64位）完成洼地填充，并基于运动流算法（Kinematic Routing Algorithm）运行流量累积模型，通过设置阈值生成“河网”。