2015 Unmanned aerial system (UAS)-derived orthoimage mosaics and digital terrain models of the NE distal lava flow margin, Holuhraun lava flow-field, Vatnajökull National Park, Iceland

Using a Phantom 3 Pro imaging system, aerial images were acquired over short section of the NE Holuhraun lava flow margin, adjacent interior and adjacent river systems. Images were initially geocoded using the device's onboard GPS and a ground control points (GCPs) network. Final products were coregistered to more precise geocoded image data collected later in 2016. Images were processed into geodetically-controlled digital terrain models (DTMs) and orthomosaics using the commercial software package Pix4Dmapper Pro version 2.0.81. In Pix4Dmapper Pro, data products were geocoded by attributing the 3D coordinates of geocoded image coregistration targets to corresponding pixels in a subset of 2D images. The 2016 image data used for coregistration utilized DGPS measurements. To estimate the localization accuracy, we used a network of N = 7 coregistration points; the resulting mean of the root mean square error (RMSE) of x, y, and z directions (i.e., latitude, longitude, and elevation) is 2.7 cm. Both the DTM and orthomosaic products have a spatial resolution of 4 cm/pixel, but the DTM has an effective resolution of ~16 cm/pixel.<br><br><b>Topic Categories (ISO 19115)</b>elevation, geoscientificinformation, imageryBaseMapsEarthCover<br><br><b>Feature and Attribute Definitions</b>A georeferenced raster displaying elevation data generated from digital camera image data using multi-view stereophotogrammetry methods.<br><b>Date of Content</b>2015-09-04<br><br><i>For inquiries regarding the contents of this dataset, please contact the Corresponding Author listed in the README.txt file. Administrative inquiries (e.g., removal requests, trouble downloading, etc.) can be directed to [e-mail]</i><br><i>This item is part of Unmanned aerial system (UAS)-derived orthoimage mosaics and digital terrain models of the northeastern portion of the Holuhraun lava flow-field, Iceland</i><br>

研究采用Phantom 3 Pro成像系统，在Holuhraun熔岩流东北边缘的一小段区域、邻近的内部区域及周边河流系统上空采集了航空影像。影像最初通过设备机载GPS及地面控制点（GCPs）网络进行地理编码，最终产品与2016年晚些时候采集的更精确地理编码影像数据完成配准。利用商业软件包Pix4Dmapper Pro 2.0.81版本，影像被处理为大地测量控制的数字地形模型（DTMs）和正射镶嵌图；在该软件中，通过将地理编码影像配准目标的三维坐标赋予二维影像子集的对应像素，实现数据产品的地理编码。用于配准的2016年影像数据采用了差分全球定位系统（DGPS）测量。为评估定位精度，研究使用了包含7个配准点的网络；x、y、z方向（即纬度、经度和高程）的均方根误差（RMSE）均值为2.7厘米。DTM和正射镶嵌图产品的空间分辨率均为4厘米/像素，但DTM的有效分辨率约为16厘米/像素。<br><br><b>主题类别（ISO 19115）</b>高程、地球科学信息、影像底图与地表覆盖<br><br><b>要素与属性定义</b>一种地理参考栅格，展示通过多视立体摄影测量方法从数码相机影像数据生成的高程数据。<br><b>内容日期</b>2015-09-04<br><br><i>关于数据集内容的咨询，请联系README.txt文件中列出的通讯作者。行政咨询（如移除请求、下载问题等）可发送至[e-mail]</i><br><i>本项是冰岛Holuhraun熔岩流场东北部区域无人机系统（UAS）衍生正射影像镶嵌图及数字地形模型的一部分</i><br>