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Optical Volume Scattering Function and Depolarization Sensor


Sequoia Scientific

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°. Of this, the range 0.094 to 14.9° is covered with Sequoia’s 32-ring detector optics as in the LISST-200X. From 15 to 150° scattering from the length of a laser is viewed by a rotating eyeball. These data produce P12 and a noisy estimate of P22 (no P22 estimate at 45 and 135°).

- In-situ measurements of P11, P12 and P22 (noisy) elements of scattering Mueller matrix, (P11 is VSF) from 15-150º (no P22 estimate at 45 and 135°).
- 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.


Brochure LISST-VSF - Download
Sequoia Scientific Product Catalog 2020 - Download

Manuale LISST-VSF - Download

Technical Papers
Calibration of the LISST-VSF to derive the volume scattering functions in clear waters - Download