Satellite video and individual image frames from the Tanana River, Alaska, July 14, 2020, for Particle Image Velocimetry

This data release consists of a video and individual image frames extracted from the original high frame rate video and used to derive remotely sensed estimates of surface flow velocity via particle image velocimetry (PIV). These data were acquired from the Tanana River near Nenana, Alaska, on July 14, 2020. The video was obtained from a satellite operated by Planet Labs as part of the SkySat constellation. The original video was recorded at 30 frames per second and is provided in a compressed, lower-resolution .mp4 format video file for viewing. In addition, Planet Labs provided the individual frames comprising the video as full resolution TIFF images. This data release consists of individual frames extracted at a reduced frame rate of 1 frame per second (1 Hz). The original images were not geo-referenced and had to be stabilized to account for motion of the satellite platform during acquisition. Image stabilization was performed using the TrakEM2 plugin to the ImageJ software package. The stabilized image sequence was then geo-referenced in the Global Mapper software package using tie points selected from an orthophoto of the Tanana River study area available from a related data release. A spatial transformation based on these tie points and control points was derived in MATLAB and then applied to the images to project them into the UTM Zone 6N, NAD83 coordinate system. The resulting geo-referenced images had a spatial resolution (pixel size) of 0.925 m and effectively stabilized the image sequence prior to PIV analysis. The grayscale images were saved as TIF files with corresponding world files (*.tfw) that contain the spatial referencing information for each image. The sequence consists of 17 individual images representing 17 seconds of data collection. The entire sequence of TIF images and world files is contained within a zip archive.