Orthomosaic photographs of areas surrounding Toolik Field Station, Alaska, 2002

The Toolik Field Station GIS (geographic information system) Department (ToolikGIS) has contracted the collection of aerial photographs of high-use research areas around Toolik Field Station during years 2002, 2007, 2013 and 2018. The aerial photographs were collected from small fixed wing aircraft during the summer months of July or August. Each photograph consists of a red, green, and blue spectral band. Photographs of each research area were collected with a high degree of front and side overlap. The overlapping photographs of each research area, by year, were merged using Adobe Photoshop, photogrammetry and/or GIS software. When available, GNSS (Global Navigation Satellite System) data were used during processing to create spatially referenced and terrain-corrected orthophotographic mosaics (ie, orthophotos). ToolikGIS uses orthophotos to help scientists select new research sites and support terrestrial change detection analyses. This orthophoto collection was created to serve primarily as a basemap in a GIS to support scientific research activities operating out of Toolik Field Station. When viewed in concert with corresponding orthographic photographs from 2007, 2013, and 2018, preliminary change detection analyses may be possible. This dataset contains orthomosaic photographs from Toolik Field Station in 2002.

Toolik野外站地理信息系统（GIS，geographic information system）部门（以下简称ToolikGIS）承接了2002、2007、2013与2018年Toolik野外站周边高频使用研究区域的航空摄影采集项目。该类航空影像通过小型固定翼飞机，于每年7月或8月的夏季月份采集完成。每张影像包含红、绿、蓝三个光谱波段。各研究区域的影像均以较高的航向与旁向重叠度进行采集。每年采集的各研究区域重叠影像，均通过Adobe Photoshop、摄影测量软件及/或地理信息系统软件完成拼接融合。处理过程中若有可用的全球导航卫星系统（GNSS，Global Navigation Satellite System）数据，将用于生成具备空间参考性且经过地形校正的正射影像镶嵌图（简称正射影像）。ToolikGIS依托正射影像辅助科研人员遴选新研究站点，并支撑地表变化检测分析工作。本正射影像数据集主要作为地理信息系统底图，服务于Toolik野外站开展的各类科学研究活动。将本数据集与2007、2013及2018年对应的正射影像结合查看，可开展初步的变化检测分析。本数据集包含Toolik野外站2002年的正射镶嵌影像。