Base spectral datasets used for modelling in the publication "Radiometric Sensitivity Requirements For Live Coral Reef and Seagrass Detection using Spaceborne Imaging Spectroscopy"

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The collection contains 1) base average spectral reflectance endmembers for different benthic types that have been used to define and model changes in community reflectance in the above publication submission. e.g. Algae, live coral, turf, sand, and Coraline and crusting algae; 2) phytoplankton absorption spectra for modelling different water columns conditions as outlined in the paper.
Lineage: For the benthic types: The six endmembers were derived by grouping and averaging relevant spectra from an existing spectral library of approximately 160 endmembers, collected from representative reefs in Fiji (Solo, Suva, and Navakavu). This library captures the characteristic spectral signatures of benthic types commonly found in coral reef environments. In summary, an Ocean Optics USB2000 spectrometer setup in an underwater housing was used to obtain spectral measurements by a SCUBA diver. The spectral endmembers were measured using the underwater spectrometer with illumination from a standard halogen dive light to compensate for loss of downwelling light. Reflected radiance (Lu) from target benthic features (e.g., coral or macro algae) between 1-5 m depth and at a consistent distance from the instrument were measured eight times after measurement of a calibration surface and a dark target. The final endmember for each target was calculated as an average of the eight Lu corrected and calibrated reflectance signatures.
The phytoplankton absorption spectra are taken from two sites - a subtropical coastal embayment and an offshore coral reef in a tidal environment using measured inherent optical properties (IOPs) (vertical attenuation coefficients (Kd), backscattering, scattering, absorption and reflectances) collected at two sites within the Australian East Marine Bioregion. These were: a relatively clear water column (“clear water”) site at Heron Reef, located in the southern portion of the Great Barrier Reef, Australia (Lat: -23.438, Long: 151.901), and a more turbid water column (“clear-turbid water”), collected in the coastal embayment of Moreton Bay, Australia (Lat: -27.215, Long: 153.348)