VEDA

Visible-light Extinction with Depth Analysis

App developed by Remote Sensing Laboratory, Goa University, India. The work was funded by Naval Research Board under the sanction letter DNRD/0100/NRB/4179/D.

About app: Be the expert in understanding underwater light attenuation in coastal and estuarine waters of Goa, India. This application provides various parameters, such as, attenuation coefficients and vertical visibility, using in-situ measurements and numerical modeling. The parameters are provided with respect to bottom depth, season, tidal phase, and sun zenith angle.

About data: The data includes 22 sampling locations, at which in-situ measurements were collected in each season, i.e., Indian Summer Monsoon (ISM), post-ISM, and pre-ISM, between September, 2019 and January, 2023. The in-situ measurements were collected using a HyperOCR Hyperspectral Ocean Color Radiometer assembly that comprised hyperspectral downwelling irradiance and upwelling radiance sensors, fluorescence sensors, backscattering sensor at 700 nm, water temperature, conductivity, pressure and tilt sensors.

Derived Parameters: The estimation of diffuse attenuation coefficient of downwelling irradiance at 490 nm (K_d⁴⁹⁰) was performed from in-situ measurements. The computations of attenuation coefficients (γ,γ₁,γ₂) were performed following Paulson & Simpson (1977), while the vertical visibility computations were adapted from Preisendorfer (1986).