Aquatic Sciences Meeting, Albuquerque 2001

CS24 Optics

Date: Tuesday, February 13, 2001, Time: 4:15:00 PM

Location: Sandia/Santa Ana

Phinney, D, A, Bigelow Laboratory for Ocean Sciences, W. Boothbay Harbor, ME, USA, dphinney@bigelow.org

Yentsch, C, S, Bigelow Laboratory for Ocean Sciences, W. Boothbay Harbor, ME, USA, csyentsch@bigelow.org

THE EFFECT OF WATER DEPTH ON THE REMOTE SENSING OF BENTHIC COMMUNITIES THROUGH CLEAR OCEAN WATERS

The spectral distribution of water-leaving radiance available to ocean color sensors is a function of the optical properties of the water, the spectral reflectance of the bottom and water depth. We have measured these parameters in coral reef environments where benthic optical properties affect the spectral distribution of light exiting the ocean. The double pathlength effect introduced by propagating incident solar irradiance downward and reflected radiance upward is the most important factor affecting degradation of benthic spectral signatures. We used direct measurements of water column IOPs, hyperspectral water-leaving radiance and hyperspectral benthic reflectance of carbonate sand, coral and macroalgal communities over depth gradients as inputs to Sequoia Scientific's HYDROLIGHT software in order to develop a training dataset for evaluation of simplified simulations. The discrimination of bottom types using remotely sensed ocean color in clear water requires prior knowledge of the bathymetry in all but the shallowest regions as spectral degradation due to water depth leads to the discrimination of only 'dark' versus 'bright' bottom types representing highly absorbing, photosynthetic communities and highly reflective benthic sediments such as by carbonate sand, respectively.

Return to This Session's Schedule · Complete Session Listing ·

Aquatic Sciences Meeting, Albuquerque 2001

Quicklinks