Ra. Maffione et Dr. Dana, INSTRUMENTS AND METHODS FOR MEASURING THE BACKWARD-SCATTERING COEFFICIENT OF OCEAN WATERS, Applied optics, 36(24), 1997, pp. 6057-6067
The backward-scattering coefficient b(b) is an important optical prope
rty that plays a central role in studies of ocean-color remote sensing
, suspended particle distributions, water clarity, and underwater visi
bility. We investigate the fixed-angle backscattering sensor approach
for the application of measuring b(b). Analysis shows that the sensor
response to volume scattering can be expressed as the integral of the
volume scattering function (VSF) over the backward angles (90-180 degr
ees) weighted by the sensor-response function. We present a procedure
for determining the sensor-response function that contains all the inf
ormation necessary to calibrate the sensor fully to measure the VSF at
a nominal backscattering angle. It is shown that, for fixed-angle bac
kscattering sensors, b(b) is most accurately estimated when the sensor
-response function covers the middle range of backscattering angles, r
oughly 110-160 degrees, where the shape of the VSF has the least varia
bility. Backscattering at and near the end angles, namely, 90 degrees
and 180 degrees, are least correlated with b(b). We describe a variety
of spectral backscattering sensors that we have developed, and we pre
sent their sensor-response functions. (C) 1997 Optical Society of Amer
ica.