The Feasibility of using Inherent Optical Properties and the Apparent Optical Property Remote Sensing Reflectance to estimate Suspended Particulate Matter, Particularly for use in Airborne Hydrographic Surveys

Airborne hydrographic surveys are routinely used to create and update nautical charts around the world. This research is intended to assist in maximizing the utility of the data products made available from those surveys in accordance with the current survey–once, use–many–times initiatives. Specifically, this project evaluates the feasibility of using the data available airborne hydrographic systems that utilize bathymetric lasers and hyperspectral sensors to estimate the concentration of suspended particulate matter (SPM). SPM is sometimes also called suspended sediment. The ability to chart spatial distributions of SPM utilizing hydrographic survey systems already in operation will assist researchers, managers, and stakeholders of the areas thus surveyed. Ship-based in situ measurements of multiple IOPs at up to twelve wavelengths were gathered in the northern Gulf of Mexico during five cruises between 2009 and 2010. One hundred sixty-nine IOP based SPM models using all available quality-checked data were developed and evaluated for performance. This large number of algorithms allowed for a comparison of the effectiveness of the IOPs that may be derived from airborne hydrographic surveys with other IOPs that may or may not be so readily available. The results were varied. The apparent optical property remote sensing reflectance (Rrs) is a data product of hyperspectral sensors that are often part of airborne survey systems. A method to predict suspended particulate matter concentration using the wavelength of maximum intensity for Rrs is presented. This represents a new way to estimate suspended particulate matter concentration from an airborne platform. Due to the methods used for gathering the in-situ data, it was necessary to consider the validity of the assumption that consecutive water column profiling events from a ship represent the same sampling environment. Though this research demonstrates that this assumption is false, it does indicate that consecutive profiling events do sample the same water properties in many instances and that with a little care, datasets gathered this way may be used in research efforts similar to this one. Finally, the distribution and selected properties of SPM concentrations in the northern Gulf of Mexico were examined