Continued Development and Evaluation of the D-2 Inc. Hybrid CTD Sensor

Conductivity-Temperature-Depth (CTD) sensors, a mainstay of ocean observing, are routinely deployed from ships and fitted to autonomous instrument systems including moorings, profiling floats, gliders and AUVs. A recently-developed CTD sensor from D-2, Inc. is described and performance assessments based on laboratory calibration work and observations piggy-backed on research cruises are reviewed. The ocean observations were implemented using self-contained controller/data logger/battery units developed for this project; this subsystem is also documented. The work concludes with a discussion of further envisioned refinements to the CTD.