Moorings and Drifters for Real-Time Interdisciplinary Oceanography

Abstract

A telemetering electronics/control unit (OASIS) has been developed for use on moorings and free-floating drifters. The OASIS controllers are part of a long-term “coastal ocean observatory,” consisting of an infrastructure of ships, submersibles, an array of remote sensing platforms (moorings, drifters), communication links between sensors and laboratory, and data management facilities. The OASIS controller coordinates retrieval of data from a varying array of up to 28 oceanographic sensors, which may output digital, analog, or frequency data. The controller provides scheduling, sensor control software, data logging, preliminary data processing, and two-way telemetry between remote platform and ship or shore station. Telemetry allows real-time access to data and permits users to alter control parameters as necessary. Two OASIS moorings have been successfully deployed off the central California coast since 1992. Real-time access and two-way telemetry has allowed the moorings to become testbeds for the deployment of new sensors and widely used observational and planning tools. Over longer timescales the moorings will be an important tool for tracking environmental variability. OASIS drifters have been tested in 11 deployments off California and 3 deployments in the equatorial Pacific. This paper describes the OASIS controller, its deployment on moorings and drifters, and presents oceanographic data that demonstrate the types of information obtained both from central California and the equatorial Pacific.