This data release includes field spectra collected from a boat during a tracer experiment performed on the Missouri River near Lexington, Missouri, on May 11, 2024. One of the primary goals of this study was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) in a large, highly turbid natural river channel using data from a Uncrewed Aircraft Systems (UAS)-based hyperspectral imaging system. Previous research on remote sensing of tracer dye concentrations demonstrated the ability to obtain moderately precise concentration estimates from standard red-green-blue (RGB) video and orthophotos and this experiment allowed us to evaluate the hypothesis that more detailed spectral information could enable concentrations to be inferred with greater accuracy and precision. The broader objective motivating tracer studies along the Missouri River is to gain insight regarding the dispersion processes that influence the movement and survival of endangered sturgeon larvae. This data release provides access to a data set obtained to support this experiment: Field spectra recorded along a channel cross section as the plume of Rhodamine WT dye passed by. The data consist of reflectance measurements obtained above the water surface over the wavelength range from 400-900 nm. Please refer to the metadata file for further detail about this data set. Overall, these data were used to assess the potential for estimating tracer dye concentrations in turbid rivers from UAS-based hyperspectral image data.

This child data release includes field spectra and in situ measurements of Rhodamine WT dye concentration acquired during a tracer experiment performed on the Missouri River near Columbia, Missouri, on May 5, 2021. One of the primary goals of this tracer experiment was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) from various types of remotely sensed data in a large, highly turbid natural river channel. Previous research on remote sensing of tracer dye concentrations has focused on clear-flowing streams, but the Missouri River is much more turbid. As a result, the effect of the dye on the reflectance of the water could be obscured by the effects of suspended sediment on reflectance. This experiment thus provided an initial test of the potential to map dye concentrations from remotely sensed data in more turbid rivers like the Missouri. The experiment involved introducing a pulse of Rhodamine WT dye into the channel at an upstream transect and then observing the dispersion of the dye along the river using various in situ and remote sensing instruments. For example, field spectra were used to quantify the reflectance characteristics of the water as the dye concentration varied over the course of the experiment. An ASD HandHeld2 Pro spectroradiometer deployed from a boat was used to record field spectra from above the water surface in reflectance mode, with periodic measurements from a Spectralon panel serving as the white reference. A separate set of of field spectra was collected on each traverse of a channel cross-section. Data from four such transects, each spanning about ten minutes in time, is included in this data release. Each spectrum was subjected to a third-order Savitzky-Golay smoothing filter applied twice over a 15 nm window and then subset to the wavelength range from 400-900 nm. In addition to the spectra, a Trimble Geo7X handheld GPS receiver was used to record spatial coordinates as the boat traversed the channel and a Turner C3 submersible fluorometer (sonde) was used to measure the Rhodamine WT dye concentration in parts per billion (ppb). The dye concentration at each spectral measurement location was interpolated in time based on the sonde data by pairing time stamps from the spectra with those from the sonde. This data release provides both the reflectance spectra and the interpolated dye concentrations, as well as locations and time stamps, and can be used to develop relationships between concentration and reflectance for mapping dye dispersion in river channels from field spectra or passive optical remotely sensed data. The field spectra from throughout the experiment are compiled in a single file, MissouriDyeFieldSpectra.csv, and organized by cross-section number. The file also includes columns for the UTC time of the spectrum, the easting and northing spatial coordinates (UTM Zone 15S, NAD83), and the interpolated dye concentration in ppb. The remaining columns are for the reflectance at each wavelength from 400-900 nm in 1 nm increments.

This data release includes in situ measurements of Rhodamine WT dye concentration acquired during a tracer experiment performed on the Missouri River near Lexington, Missouri, on May 11, 2024. One of the primary goals of this study was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) in a large, highly turbid natural river channel using data from a Uncrewed Aircraft Systems (UAS)-based hyperspectral imaging system. Previous research on remote sensing of tracer dye concentrations demonstrated the ability to obtain moderately precise concentration estimates from standard red-green-blue (RGB) video and orthophotos and this experiment allowed us to evaluate the hypothesis that more detailed spectral information could enable concentrations to be inferred with greater accuracy and precision. The broader objective motivating tracer studies along the Missouri River is to gain insight regarding the dispersion processes that influence the movement and survival of endangered sturgeon larvae. This data release provides access to two data sets obtained to support this experiment: 1. In situ measurements of Rhodamine WT dye concentration collected by a sonde deployed from a boat as field spectra (see related child item). 2. In situ measurements of Rhodamine WT dye concentration collected by a sonde attached to a fixed buoy located within the spatial footprint of the hyperspectral images (see related child item). The spatial coordinates of the buoy are stored in a separate file. Please refer to the metadata file for further detail about these data sets. Overall, these data were used to assess the potential for estimating tracer dye concentrations in turbid rivers from UAS-based hyperspectral image data.

This data release includes in situ measurements of Rhodamine WT dye concentration acquired during a tracer experiment performed on the Missouri River near Lexington, Missouri, on May 11, 2024. One of the primary goals of this study was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) in a large, highly turbid natural river channel using data from a Uncrewed Aircraft Systems (UAS)-based hyperspectral imaging system. Previous research on remote sensing of tracer dye concentrations demonstrated the ability to obtain moderately precise concentration estimates from standard red-green-blue (RGB) video and orthophotos and this experiment allowed us to evaluate the hypothesis that more detailed spectral information could enable concentrations to be inferred with greater accuracy and precision. The broader objective motivating tracer studies along the Missouri River is to gain insight regarding the dispersion processes that influence the movement and survival of endangered sturgeon larvae. This data release provides access to two data sets obtained to support this experiment: 1. In situ measurements of Rhodamine WT dye concentration collected by a sonde deployed from a boat as field spectra (see related child item). 2. In situ measurements of Rhodamine WT dye concentration collected by a sonde attached to a fixed buoy located within the spatial footprint of the hyperspectral images (see related child item). The spatial coordinates of the buoy are stored in a separate file. Please refer to the metadata file for further detail about these data sets. Overall, these data were used to assess the potential for estimating tracer dye concentrations in turbid rivers from UAS-based hyperspectral image data.

This data release includes in situ measurements of flow velocity acquired during a tracer experiment performed on the Missouri River near Lexington, Missouri, on May 11, 2024. One of the primary goals of this study was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) in a large, highly turbid natural river channel using data from a Uncrewed Aircraft Systems (UAS)-based hyperspectral imaging system. Previous research on remote sensing of tracer dye concentrations demonstrated the ability to obtain moderately precise concentration estimates from standard red-green-blue (RGB) video and orthophotos and this experiment allowed us to evaluate the hypothesis that more detailed spectral information could enable concentrations to be inferred with greater accuracy and precision. The broader objective motivating tracer studies along the Missouri River is to gain insight regarding the dispersion processes that influence the movement and survival of endangered sturgeon larvae. This data release provides access to a data set obtained to support this experiment: field measurements of flow velocity obtained using an acoustic Doppler current profiler (ADCP) deployed from a boat along two channel cross sections, one above and one below the transect captured by the hyperspectral imaging system. Please refer to the metadata file for further detail about this data set. Overall, these data were used to assess the potential for estimating tracer dye concentrations in turbid rivers from UAS-based hyperspectral image data.

This child data release includes field spectra and in situ measurements of turbidity and Rhodamine WT dye concentration acquired during an experiment performed at the USGS Columbia Environmental Research Center, near Columbia, Missouri, on April 2, 2019. The purpose of the experiment was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) tracer from various types of remotely sensed data in water with varying levels of turbidity. Whereas previous research on remote sensing of tracer dye concentrations has focused on clear-flowing streams, the Missouri River is much more turbid and the reflectance signal associated with the sediment-laden water could obscure that related to the presence and amount of dye. This experiment thus provided an initial test of the potential to map dye concentrations from remotely sensed data in more turbid rivers like the Missouri, where tracer studies involving the release of a visible dye can provide insight regarding the dispersal of endangered sturgeon larvae. The experiment involved manipulating the turbidity and Rhodamine WT dye concentration in two water tanks and using field spectra to quantify the reflectance characteristics of the water as the turbidity and dye concentration varied over the course of the experiment. The field spectra were recorded from above the water surface using an ASD HandHeld2 Pro spectroradiometer in reflectance mode, with periodic measurements from a Spectralon panel serving as the white reference. Each set of field spectra consisted of a total of 40 measurements from a given tank, made every 15 seconds; the turbidity and dye concentration was assumed to be fairly constant during this 10-minute time period. The individual spectra were subjected to a third-order Savitzky-Golay smoothing filter applied twice over a 15 nm window and then subset to the wavelength range from 400-900 nm. The field spectra from throughout the experiment are compiled in a single file, TankSpectra.csv, and organized by the nominal levels of turbidity and dye concentration and field spectra set number. The file also includes columns for the actual measured turbidity and dye concentration, averaged over the 10-minute time period during which each set of spectra was recorded. The reflectance at each wavelength from 400-900 nm is given in a separate column of the file.

This child data release includes field spectra and in situ measurements of turbidity and Rhodamine WT dye concentration acquired during an experiment performed at the USGS Columbia Environmental Research Center, near Columbia, Missouri, on April 2, 2019. The purpose of the experiment was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) tracer from various types of remotely sensed data in water with varying levels of turbidity. Whereas previous research on remote sensing of tracer dye concentrations has focused on clear-flowing streams, the Missouri River is much more turbid and the reflectance signal associated with the sediment-laden water could obscure that related to the presence and amount of dye. This experiment thus provided an initial test of the potential to map dye concentrations from remotely sensed data in more turbid rivers like the Missouri, where tracer studies involving the release of a visible dye can provide insight regarding the dispersal of endangered sturgeon larvae. The experiment involved manipulating the turbidity and Rhodamine WT dye concentration in two water tanks and using field spectra to quantify the reflectance characteristics of the water as the turbidity and dye concentration varied over the course of the experiment. The field spectra were recorded from above the water surface using an ASD HandHeld2 Pro spectroradiometer in reflectance mode, with periodic measurements from a Spectralon panel serving as the white reference. Each set of field spectra consisted of a total of 40 measurements from a given tank, made every 15 seconds; the turbidity and dye concentration was assumed to be fairly constant during this 10-minute time period. The individual spectra were subjected to a third-order Savitzky-Golay smoothing filter applied twice over a 15 nm window and then subset to the wavelength range from 400-900 nm. The field spectra from throughout the experiment are compiled in a single file, TankSpectra.csv, and organized by the nominal levels of turbidity and dye concentration and field spectra set number. The file also includes columns for the actual measured turbidity and dye concentration, averaged over the 10-minute time period during which each set of spectra was recorded. The reflectance at each wavelength from 400-900 nm is given in a separate column of the file.

Field spectra were collected from the Kootenai River in northern Idaho during a tracer dye experiment on September 25, 2017, to assess the potential for inferring concentrations of Rhodamine WT dye from remotely sensed data. Reflectance measurements were made from a boat near the confluence with Ball Creek with the Kootenai River using an Analytical Spectral Devices FieldSpec3 spectroradiometer operated in reflectance mode. The Rhodamine WT dye concentration at each spectral measurement location was interpolated from field measurements of concentration obtained with a Turner Designs C3 submersible fluorometer (sonde) by pairing time stamps from the spectra with those from the sonde. This data release provides both the reflectance spectra and the interpolated dye concentrations, as well as locations and time stamps, and can be used to develop relationships between concentration and reflectance for mapping dye dispersion in river channels from field spectra or passive optical remotely sensed data.

Field spectra were collected from a reach of the upper Sacramento River in northern California, September 11-14, 2017, to support research on remote sensing of rivers. Reflectance measurements were made from a boat near the confluence of Cottonwood Creek with the Sacramento River using an Analytical Spectral Devices FieldSpec3 spectroradiometer operated in reflectance mode. The depth at each spectral measurement location was interpolated from field measurements of depth obtained with an acoustic Doppler current profiler and an echo sounder. This data release provides both the reflectance spectra and the interpolated depths and can be used to develop relationships between depth and reflectance for mapping river bathymetry from field spectra or passive optical remotely sensed data.

This data release includes MATLAB source code associated with a manuscript titled "Hyperspectral Image Transects during Transient Events in Rivers (HITTER): Framework development and application to a tracer experiment on the Missouri River, USA" that was developed to support a tracer experiment performed on the Missouri River near Lexington, Missouri, on May 11, 2024. One of the primary goals of this study was to assess the feasibility of inferring concentrations of a visible dye (Rhodamine WT) in a large, highly turbid natural river channel using data from a Uncrewed Aircraft Systems (UAS)-based hyperspectral imaging system. Previous research on remote sensing of tracer dye concentrations demonstrated the ability to obtain moderately precise concentration estimates from standard red-green-blue (RGB) video and orthophotos and this experiment allowed us to evaluate the hypothesis that more detailed spectral information could enable concentrations to be inferred with greater accuracy and precision. The broader objective motivating tracer studies along the Missouri River is to gain insight regarding the dispersion processes that influence the movement and survival of endangered sturgeon larvae. A total of eight *.m files are provided below to illustrate how the HITTER approach is implemented within the context of this particular case study on the Missouri River, and seven of the *.m files are general functions that could be applied to other, similar data sets with appropriate modifications of input parameters and file paths. More specifically, the following *.m files are included: 1. ProcessingLogNanoDye.m: a script intended to be run in sequence, with the various sections of the script corresponding to different steps in the HITTER framework by calling the remaining functions in this list. 2. nanoTrajectory.m: import trajectory information recorded during a UAS flight along with the frame index used to link trajectories to specific scan lines from the hyperspectral imaging system; 3. getHoverCubes.m: interactively select hyperspectral data cubes for further processing; 4. projectLine.m: project individual pixels along hyperspectral scan lines into real-world spatial coordinates based on the trajectory information; 5. linkLine2cube.m: link data cubes to projected scan line spatial coordinates and resample the hyperspectral data to a reduced set of output times; 6. sonde4nano.m: link hyperspectral image transects to field measurements of dye concentration; 7. genObraLin.m: perform Optimal Band Ratio Analysis (OBRA) to establish an empirical relationship between dye concentration and spectral reflectance, using source code originally developed for estimating water depth following the approach summarized by Legleiter and Harrison (2019) and included in the Optimal River Bathymetry Toolkit (Legleiter, 2020; Legleiter, 2021); and 8. cube2dyeMap.m: create a map of estimated dye concentrations from a processed hyperspectral data cube using an OBRA relationship derived using genObraLin.m, with a custom colormap from the crameri.m file that can be obtained via the link provided below. The *.m files are thoroughly documented, with numerous comments to facilitate understanding of the code, but the user will need to update input parameters and file paths before attempting to use this code to apply the HITTER framework to a different data set. The code was developed in MATLAB R2024a (Version 24.1) with the Image Processing and Mapping Toolboxes (https://www.mathworks.com/products/matlab.html). Please note that the code is made available without warranty or support, as described in the distribution liability section of the metadata associated with this data release.