Multispectral scattering measurements along extended paths over the ocean surface using an imaging system

A new instrument has been developed for measurement of visibility and scattering characteristics in the visible spectrum over extended paths. The instrument, a Multispectral Scattering Imager, is designed to acquire calibrated radiance images in several wavelengths over extended paths. From measurements of the horizon radiance and the radiance of dark targets, combined with measurements of the inherent properties of the dark targets, visibility and effective scattering coefficient over the integrated path can be determined. The instrument has acquired several months of data over a 7.2 km path in San Diego, along with several transmissometers and nephelometers. Initial data comparisons show quite good comparisons with the other systems. The instrument has the advantage that measurements may be taken over extended paths in the wavelengths of choice, yet it is passive, and does not require an active two-ended transmitter/receiver system. We will show the results from the MSI in blue, green, red, and NIR wavebands, and show comparisons with other instruments.