World’s first autonomous, submersible instrument for measuring the volume scattering function (VSF) of water with depolarization. Measures P11, P12 and P22 elements of Mueller matrix of water. Also beam attenuation c and scattering b.

The LISST-VSF covers the angular range from 0.094 to 150 degrees. Of this, the range 0.094 to 14.9 degrees is covered with Sequoia’s 32-ring detector optics as in the LISST-200X. From 15 to 150 degrees scattering from the length of a laser is viewed by a rotating eyeball. These data produce P12 and P22.

Features

• In-situ measurements of P 11, P12 and P22 elements of scattering Mueller matrix, (P11 is VSF) from 15-150º.

• VSF (P11) only at small angles, 0.09 to 10º in 32 logarithmic steps in angles.
• Only two detectors employed with absolute radiant sensitivity (A/W) calibration.
• Beam attenuation measured with optics similar to our LISST-100X/200X.
• Roving Eyeball™ optics permit 1-degree resolution in angles between 15 -150º.
• Sampling rate at 4 seconds per measurement set (involves 2 turns of Roving Eyeball with vertical, and horizontal laser polarization).
• Daylight rejection by laser modulation.
• Dynamic range in VSF measurements extended via laser power dimming.
• Data from small and large angles in a single data stream, including depth and temperature.