Abstract
A second generation Bio-optical Profiling System (BOPS) has been designed, built and used extensively at sea. The BOPS- II is an oceanographic instrument sued to measure in-water optical, biological and physical properties in support of interdisciplinary programs. Significant advances beyond BOPS-I include: a depth capability of 500 m; more rapid data acquisition for higher water column resolution; lower inherent dark signal giving greater sensitivity; and greater multicomponent capability, permitting a wide range of additional sensors. The BOPS-II has a proven record of reliability supporting sampling strategies using ship, mooring, aircraft, and satellite optical sensors for ocean research. Rather than an article about a newly designed instrument, this is a report of an instrument and its optical calibration that has been sued routinely for nearly a decade, often in the most extreme environments of the world's oceans. An example of optical calibration history is included since calibrations are among the most important aspects of ocean optical measurements, whether in support of a single filed experiment or of long-term data collection. The BOPS instrument has served as a model for new generations of optical profiling sensors.
