This child data release includes field spectra obtained as part of a study focused on mapping salmon spawning locations along the American River near Sacramento, California, via remote sensing; the data were collected November 5-7, 2018. The purpose of this study was to develop and test a spectrally based technique for identifying salmon spawning locations, known as redds, from various types of remotely sensed data. Traditionally, redds have been mapped by eye while walking the bank or from a boat, or by an observer in an aircraft or an interpreter visually examining aerial images. The goal of this proof-of-concept investigation was to assess the potential for more efficient, objective, and automated redd mapping from conventional true color (RGB, or red/green/blue) and hyperspectral images. The field spectra were recorded from above the water surface at redds mapped in the field using an ASD HandHeld2 Pro spectroradiometer in reflectance mode, with periodic measurements from a Spectralon panel serving as the white reference. For each redd location, spectra were recorded for the pot and tail of each redd and the adjacent undisturbed substrate. The data consist of reflectance measurements over the wavelength range from 325 to 1075 nm, along with the spatial coordinates and water depth for the redd.
Field spectra from 20 redds are compiled in a single file, ReddSpectra.csv, and organized by redd, with a pot, tail, and undisturbed spectrum from each redd. The file also includes colums for the easting and northing spatial coordinates, bed elevations, and water depths. The reflectance at each wavelength from 325 to 1075 nm is given in a separate column of the file. No post-processing of the raw spectra measured in the field was performed. These data were used to assess the potential for identifying salmon spawning locations from various types of remotely sensed data.