R/V John Martin
R/V John H. Martin

The Compact-Optical Profiling System (C-OPS) is an in situ water-based radiometer system developed at Biospherical Instruments. It measures vertical profiles of ocean radiance and irradiance from 150 to 300 m depth. It consists of two radiometers operating across the 250-1650 nm wavelength range. C-OPS has a typical sampling rate of 125 Hz and a vertical resolution of less than 1 cm. It also includes ancillary sensors that measure water temperature, pressure, and humidity.

The HyperPro II is an in situ, free-fall profiling system developed by Sea-Bird Scientific to measure ocean optical properties. It includes three hyperspectral radiometers and a profiling frame with sensors for conductivity, temperature, and pressure. One radiometer points upward to measure downwelling irradiance, another points downward to measure upwelling radiance, and the third is mounted on the ship to measure incoming solar irradiance. The radiometers operate from 350 to 900 nm with a spectral resolution of 10 nm. The HyperPro II is deployed from behind the research vessel and free-falls at approximately 30 cm/s.

Sunphotometers are passive optical sensors that measure the amount of sunlight. They are pointed directly at the sun to measure direct sunlight, not sunlight scattered by aerosols. These measurements can be used to determine aerosol optical depth by applying Beer’s Law. Sunphotometers have been deployed on aircraft, research vessels, and field sites for aerosol research and monitoring.