Unmanned Aerial Systems (UAS) Multispectral & Normalized difference vegetation index (NDVI) Orthomosaics of Subset area within Circumpolar Active Layer Monitoring (CALM) grid Toolik Lake, Alaska, USA, 2019.

Beginning in the summer of 2018, high resolution multispectral Unmanned Aerial Systems (UAS) datasets were collected across multiple sites in northern Alaska in an effort to characterize landcover, test remote sensing scaling methods and for use in validating satellite data products. Orthomosaic datasets were developed from multispectral images acquired using a Micasense RedEdge-M sensor and using standardized structure-from-Motion (SfM) photogrammetry workflows. UAS data products reflect landscape and vegetation composition and status at time of flight. We produced two data products (1) 6 band multispectral orthomosaic of Circumpolar Active Layer Monitoring Program (CALM) subset area and (2) 1 band normalized Normalized difference vegetation index (NDVI) orthomosaic of CALM subset area. All data have been calibrated using the proprietary Micasense grey-scale reflectance panel and/or the on-board drone sun sensor. The 6 band multispectral image consists of: Band 1: Blue (475 nm center, 20 nm bandwidth), Band 2: Green (560 nm center, 20 nm bandwidth), Band 3: Red (668 nm center, 10 nm bandwidth), Band 4: Red Edge (717 nm center, 10 nm bandwidth), Band 5: Near-IR (840 nm center, 40 nm bandwidth), Band 6: NDVI (not scaled) The 1 band NDVI product consists of: Band 1: Scaled NDVI map (calculated within ArcMap)自2018年夏季起，研究团队在阿拉斯加北部的多个站点采集了高分辨率多光谱无人机系统（Unmanned Aerial Systems, UAS）数据集，旨在表征土地覆盖类型、测试遥感尺度转换方法，并用于验证卫星数据产品。研究团队采用Micasense RedEdge-M传感器采集的多光谱影像，并通过标准化的运动恢复结构（structure-from-Motion, SfM）摄影测量流程，生成了正射镶嵌数据集。无人机系统数据产品可反映飞行时刻的景观与植被组成及生长状态。本次研究共生成两类数据产品：(1) 环极活动层监测计划（Circumpolar Active Layer Monitoring Program, CALM）子区域的6波段多光谱正射镶嵌数据集；(2) CALM子区域的单波段归一化差分植被指数（Normalized Difference Vegetation Index, NDVI）正射镶嵌数据集。所有数据均通过专用的Micasense灰度反射率板及/或机载无人机太阳传感器完成校准。该6波段多光谱影像包含以下波段：波段1：蓝光波段（中心波长475 nm，带宽20 nm）；波段2：绿光波段（中心波长560 nm，带宽20 nm）；波段3：红光波段（中心波长668 nm，带宽10 nm）；波段4：红边波段（中心波长717 nm，带宽10 nm）；波段5：近红外波段（中心波长840 nm，带宽40 nm）；波段6：未缩放的NDVI。该单波段NDVI产品包含以下内容：波段1：缩放后的NDVI分布图（在ArcMap中计算生成）。