Interpretation of airborne spectral reflectance measurements over Georgian Bay

Abstract Airborne spectral measurements were made along 3 flight lines over Georgian Bay in August and October 1974. Spectral data were collected in the wavelength regions 0.44 to 0.46 μm, 0.55 to 0.59 μm, 0.68 to 0.70 μm and 0.72 to 0.75 μm using a four-channel spectral scanning photometer. The airborne spectral reflectance curves over several stations were compared with subsurface volume reflectance measurements made as part of the Canada Centre for Inland Waters 1974 Lake Huron-Georgian Bay ship cruise. These comparisons permitted an evaluation of the water surface reflection effects on the airborne data. The airborne spectral reflectance curves are then interpreted using a two-flow radiative transfer model to derive chlorophyll concentration line profiles. Correlation coefficients between calculated and ship-measured chlorophyll data range from 0.810 to 0.984.