| Summary: | The radiance distribution provides complete information regarding the geometrical
structure of the ambient light field within the ocean. A quantitative study of the radiance
field in the dynamic ocean water is presented in this thesis work. The study starts with the development of a novel radiance camera for the measurement of the full spherical
radiance distribution at the ocean surface and depth. Nonlinear response functions are
designed and advanced radiometric calibrations are developed. The resulting camera
measures the radiance distribution in absolute units over an extremely high dynamic
range at fast rates. With the newly obtained radiance data, I have examined the fine
structure of both the downwelling and upwelling radiance distribution and its variation
with depth in optically diverse water types. The fully specified radiance distribution data
are used to derive all apparent optical properties and some inherent optical properties
including the absorption coefficient. With the camera fixed at shallow depths, I have
observed and determined the sea surface wave disturbance of the radiance distribution. It is found that the radiance fluctuates anisotropically with regard to its amplitude and
periodicity. Typical spatial structures of the dynamic radiance field are identified and
shown relevant to the surface waves and the solar zenith angles. The variability in the
radiance field also propagates to the irradiance field; the variability is pronounced in
measured irradiance depth profiles in the upper layers of the ocean. The statistics of the
irradiance fluctuations along the water depth, including the dominant frequency and
coefficient of variation, are derived using wavelet techniques and fitted to novel analytic
models. The results from the irradiance depth-profile decomposition are in agreement
with theoretical models and other independent measurements. This thesis work represents the first attempt to quantify the full light field and its variability in dynamic ocean waters and is of significant relevance to many other optics-related applications.
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