The SUMOSS was designed to measure simultaneously a number of inherent and
apparent optical properties at high spectral resolution (<5 nm). The sensor
s consist of a transmissometer to measure beam attenuation, plane irradianc
e sensors (to measure reflectance, K-d and K-u) and a scalar irradiance sen
sor for calculating the absorption coefficient. The SUMOSS was designed to
minimize the effects of self-shading of the sensors. The radiometric stabil
ity of the instrument across the visible spectrum (350-720 nm) was assessed
in a series of dark room experiments. The linearity of the response of the
passive sensors was evaluated over a range of intensities and was found to
be stable to within 1%. The spectral resolution was measured using red and
green lasers on the passive channels (FWHM 4 nm, sampling interval 0.4 nm)
. Radiometric calibrations showed that there was minimal variability in the
spectral response over time. The SUMOSS has been deployed in three optical
ly different water masses (the Baltic, Mediterranean and UK) and the spectr
al quality and intensity of the readings is interpreted using measurements
of the concentrations of suspended particulate material and chlorophyll.