Thermal State of Permafrost in North America - Orthomosaic Images and Digital Surface Models for Happy Valley, Alaska, United States 2020-2024

This dataset contains orthomosaic images and digital surface models (DSMs) for an area of study near Happy Valley in northern Alaska, USA (United States of America). The data were collected to further support ongoing research that aims to assess geomorphological and environmental changes near ground temperature monitoring sites, and to provide spatial data for validation of land surface deformation models. The 2020 and 2022 flights were conducted using a DJI (Da-Jiang Innovations) Phantom 4 RTK (P4RTK) equipped with a DJI D-RTK 2 Mobile Base Station for real-time kinematic (RTK) positioning. For flight missions in 2023 and 2024, we utilized a DJI Matrice M300 RTK (M300RTK) drone equipped with a DJI Zenmuse P1 camera and a 35mm lens (45MP). An Emlid RS3 GNSS (Global Navigation Satellite System) base station was used for RTK positioning. All images were processed using Agisoft Metashape (v.2.2.0) following a standard three-dimensional mapping processing workflow utilizing ground control points measured in the field for horizontal and vertical corrections and reliable reproduction from year to year. All DSM and orthomosaic files are projected using NAD83 (North American Datum of 1983) State Plane 4 and ellipsoidal heights in meters.
The two Happy Valley sites are located on the unglaciated foothills of the Brooks Range in northern Alaska, approximately 82 miles (132km [kilometers]) south of Deadhorse along the Dalton Highway. Landcover units include tussock-graminoid, dwarf- shrub tundra and low-shrub tundra (moist acidic).