Quantification of surface suspended sediments along a river dominated coast with NOAA AVHRR and SeaWiFS measurements: Louisiana, USA.
Walker, N.D., and Myint, S.
The ability to quantify suspended sediment concentrations accurately over both time and space using satellite data has been a goal of many environmental ressearchers over the past few decades. This study utilizes data acquired by the NOAA Advanced Very High Resolution Radiometer (AVHRR) and the Orbview-2 Sea-viewing wide field-of-view (SeaWiFS) ocean colour sensor, coupled with field measurements to develop statistical models for the estimation of near-surface suspended sediments and suspended solids. 'Ground truth' water samples were obtained via helicopter, small boat and automatic water sampler within a few hours of satellite overpasses. The NOAA AVHRR atmospheric correction was modified for the high levels of turbidity along the Louisiana coast. Models were developed based on the field measurements and reflectance/radiance measurements in the visible and near infrared Channels of NOAA-14 and Orbview-2 SeaWiFS. The best models for predicting the surface suspended sediment concentrations were obtained with a NOAA AVHRR Channel 1 (580-680 nm) cubic model, Channel 2 (725-1100 nm) linear model and SeaWiFS Channel 6 (660-680 nm) power model. The suspended sediment models developed using SeaWiFS Channel 5 (545-565 nm) were inferior, a result that we attribute mainly to the atmospheric correction technique, the shallow depth of the water samples and absorption effects from non-sediment water constituents.