The C-OPS (Compact-Optical Profiling System) is a radiometer system for determining apparent optical properties in aquatic systems. It consists of two 7 cm diameter radiometers: one measuring in-water downward irradiance, and the other either upwelling radiance or upward irradiance, as well as pressure/depth, water temperature, and dual-axes tilt. Both radiometers are equipped with up to 19 optical-filter microradiometers (selected from 29 different wavelengths) and are mounted on a unique free-fall, kite-like backplane. To avoid influences from the shadow of a boat or dock, the backplane can be optimized for either slow descent rates for work in very shallow (e.g., 3 m) and coastal waters, or fast descent rates for observations in the open ocean. C-OPS is so lightweight it can be hand deployed by almost anyone, and the system can be operated from either small or large vessels. An above-water surface reference instrument is also available to measure global irradiance.
