HydroBeta - HOBI Labs

HydroBeta during deployment
(with c-Beta in center)

Instrument for measuring in-situ profiles of the Volume Scattering Function from 10° to 170°

The first and only instrument that provides real-time in-situ profiling of the VSF, HydroBeta measures the VSF at 12 angles simultaneously, at rates up to 10 samples per second. HOBI Labs has deployed HydroBeta in various water types (see data).

Approach

A collimated, de-polarized laser beam is projected into the water
12 radiometer receivers view the center of the beam at various intersection angles.
Receivers are fixed in place, but can be reconfigured for different specific angles.

Example Configuration (top view)

Laser beam is green; receiver fields of view are yellow.

HydroBeta Layou

Laser is pulsed at high frequency; receivers are synchronized to laser pulses.
Forward-angle receivers have narrow FOV (<0.5°) and lower gain to accomodate high signal and steep slope of the forward VSF
Back-angle receivers have wider FOV (up to 2.2°) and higher gain for the weaker, shallowly sloped backward VSF

Key Features and Benefits

No moving parts
Rapid, simultaneous sampling at 12 angles
Immune to background light
Open sample volume for measuring undisturbed water
Wide dynamic range
Rigorous calibration does not depend on estimating the effective sample volume.