Hyperspectral image data acquired during a tracer dye experiment on the Kootenai River, ID, September 27, 2017

To support research on dispersion in river channels, a tracer dye experiment was performed on the Kootenai River in northern Idaho, September 25-27, 2017. This data release provides access to hyperspectral image acquired during the experiment and the supporting field-based measurements of reflectance and dye concentration are available through related data releases. The hyperspectral image data were acquired by Quantum Spatial Inc. (QSI) using the ITRES CASI 1500H imaging system deployed from a Cessna Caravan manned aircraft from a flying height of 1000 m above ground level. Initial geometric and radiometric data processing was performed by ITRES and yielded images with 0.5 m pixels for each of 48 spectral bands from 380-1050 nm. Although a large mosaic assembled from parallel, north-south strips covering a larger portion of the Kootenai River valley was collected as part of this project, this data release focuses on a series of shorter flight lines that more directly followed the river's path during multiple passes that captured the progression of the dye plume at multiple points in time. The image data were radiometrically calibrated to spectral radiance units of μW cm-2 sr-1 nm-1 and formatted with 16-bit signed integers in a BSQ intertleave. The sensor manufacturer, ITRES, also performed atmospheric correction of the radiance images using the ATCOR software package, which produced output images in units of apparent surface reflectance scaled by a factor of 100 (% X 100, or reflectance X 10,000). The resulting .bsq and assocaited .hdr files are compatible with the ENVI software package. The UTC time at the beginning of each flight line is included in the .csv file describing the images to allow for synthesis with in situ measurements of Rhodamine WT dye concentration made during the experiment as the hyperspectral images were being acquired. Overall, the images and related field-based data sets were used to assess the potential for estimating tracer dye concentrations from remotely sensed data to support studies of dispersion in river channels.