The Hyperspectral Imager for the Coastal Ocean (HICO) is a hyperspectral sensor which was launched to the
International Space Station in September 2009. The Naval Research Laboratory (NRL) has been developing the Coastal
Water Signatures Toolkit (CWST) to estimate water depth, bottom type and water column constituents such as
chlorophyll, suspended sediments and chromophoric dissolved organic matter from hyperspectral imagery. The CWST
uses a look-up table approach, comparing remote sensing reflectance spectra observed in an image to a database of
modeled spectra for pre-determined water column constituents, depth and bottom type. In order to successfully use this
approach, the remote sensing reflectances must be accurate which implies accurately correcting for the atmospheric
contribution to the HICO top of the atmosphere radiances. One tool the NRL is using to atmospherically correct
HICO imagery is Correction of Coastal Ocean Atmospheres (COCOA), which is based on Tafkaa 6S. One of the user
input parameters to COCOA is aerosol optical depth or aerosol visibility, which can vary rapidly over short distances in
coastal waters. Changes to the aerosol thickness results in changes to the magnitude of the remote sensing reflectances.
As such, the CWST retrievals for water constituents, depth and bottom type can be expected to vary in like fashion. This
work is an illustration of the variability in CWST retrievals due to inaccurate aerosol thickness estimation during
atmospheric correction of HICO images.