Telemetry Buoy Data

To get an overview of the data from the monitoring array at 26.5°N and description of the instrumentation and telemetry system in use (Data download facility is restricted to project participants only), visit the RAPID-MOC Real time data website. Below is a description of the US telemetry system:

The mooring at site WB5 consists of a Sealine Data Logger system (Sound Ocean Systems, Inc.) and sixteen (16) SBE37 IMP (Inductive Modem) MicroCATs (Sea-Bird Electronics).

The Sealine Data Logger system is equipped with a surface telemetry controller unit mounted in a surface syntactic float, and a submerged data logger unit mounted in a subsurface syntactic float.

The two units are tethered together by a 100 m umbilical cable, with the subsurface float ~50 m from the surface. A schematic of the mooring can be found in the US buoy instrumentation section of the RAPID-MOC Real time data website.

The MicroCATs are clamped along 2 sections of jacketed wire mooring cable that are separated by a mid-depth syntactic float (the top section is ~2000 m long while the lower is ~3000 m); the two lengths of jacketed wire cable are linked together through the mid-depth float by an insulated electrical connector. The MicroCATs on both sections of cable over the full length of the mooring are inductively coupled to the Sealine Data Logger system in the subsurface float.

The Sealine Data Logger system is designed to provide control, data logging and telemetry for the MicroCATs. The data logger polls all the MicroCATs on a 2-hour schedule, stores the data internally, and then sends the data to the surface telemetry controller on a configured schedule.

The telemetry controller, which is fitted with a GPS receiver and an Iridium antenna and mast, sends the data at 12-hour intervals via Iridium satellite to a designated shore station (SOSI User Manual for Sealine Data Logger System, 2005).

Below is our data from the MicroCATs that were transmitted via telemetry from May 18-July 8, 2005. Although the telemetry buoy transmitted data for only 52 days, the microcats continued to log data until all 16 were recovered in October 2006.