High speed two way data communications used in the Texas Automated Buoy System (TABS)

The goal of obtaining cost effective, reliable, two-way data communications with remote instrumentation has always been a major technical challenge in the successful operation of a remote ocean observing system. Typical low-cost telemetry methods such as line-of-sight radio and cellular telephones are limited in their coverage and are not suitable for remote locations, such as offshore moored buoy platforms. Power limitations, space availability and high volumes of data, have made this goal even more difficult to achieve. Satellites have typically provided low data rates at relatively high costs compared to other telemetry methods available to near shore deployment applications. Most satellite telephone systems were designed around the needs of the trucking or rail industry, and have typically relied on either mechanically steered or large tunable mast antennas as well as high current electronics to achieve two-way data communications through geo-synchronous satellites. In 1991 a consortium comprised of twelve aerospace and telecommunication companies was formed to provide worldwide satellite telecommunications service to business, government and the public. Their purpose was to provide cost effective satellite voice and data communications to areas, which were under-serviced. They named the consortium Globalstar™ and over the next 10 years put into orbit, 48 LEO (Low-Earth-Orbit) satellites. Although primarily developed for voice communications in remote areas, Globalstar™ Satellite Communications System offers full duplex, two way, data communication through the Qualcomm GSP-1620 Packet Data Modem, at uplink and downlink speeds of 9600 bps. In January 2002, the Geochemical and Environmental Research Group (GERG) of Texas A&M University (TAMU), deployed a TABS II buoy in the Gulf of Mexico, at the Flower Garden Bank Marine Sanctuary equipped with the new modem. The small, robust antenna, low power requirements and high speed data telemetry have so far proven to be reliable and a cost effective means to achieve two way data transmission of moderate to large data volumes.