Incorporating a Hyperspectral Direct-Diffuse Pyranometer in an Above-Water Reflectance Algorithm

In situ hyperspectral remote-sensing reflectance (Rrs(λ)) is used to derive water quality products and perform autonomous monitoring of aquatic ecosystems. Conventionally, above-water Rrs(λ) estimated from three spectroradiometers which measure downwelling planar irradiance (Ed(λ)), sky radiance (Ls(λ)), total upwelling (Lt(λ)), with a scaling Ls(λ)/Ed(λ) correct for surface-reflected radiance. Here, we incorporate direct diffuse irradiance, (Edd(λ)) Eds(λ)), pyranometer (HSP) in an processing algorithm solar-tracking radiometry platform (So-Rad). HSP measurements sun glint (scaled Edd(λ)/Ed(λ) Eds(λ)/Ed(λ)) replace model-optimized terms the 3C (three-glint component) algorithm, estimates via spectral optimization modelled atmospheric properties respect measured radiometric quantities. We refer HSP-enabled method as DD (direct-diffuse) compare differences variability (assessed over 20 min measurement cycles) between function optical state using data ports Western Channel. The greatest divergence algorithms occurs blue part spectrum where has significantly lower than clearer conditions. also consider hypothetical two-sensor configuration (using only Lt(λ) spectroradiometer referred DD2) potential lower-cost solution, shown have comparable Our results support that sensor can fulfil dual role ecosystem by improving precision alongside its primary characterize aerosols.