Next-Generation Ocean Observing Systems, Part 3: Two-way, high-speed, Low Earth Orbiting Satellite Communications

Oceanography is an observational science driven by data collected from ships, moorings, satellites, AUVs, etc. Oceanographers are now beginning to contribute to global scale climate change studies, which requires distributing data to others in near-real time. With the new technology developments in satellites and AUV remote sensing, there is still a need for continuous, long-term time-series observations from moored platforms in support of climate change research, weather forecasting and prediction programs, environmental monitoring and assimilative modeling efforts in near real-time. To accomplish this, improved buoys and mooring technologies need to be utilized, new sensors and data systems with intelligent sampling and processing capability need to be incorporated, and world-wide, two-way, high-speed satellite telmetry systems need to be developed to return the data in near-real time to the resesarch and modeling efforts, and allow control of the remote platform from shore.

Presently new telemetry developments have the potential to revolutionize the way in which oceanographic studies are conducted. The limited capabilities of ARGOS and GOES have been heavily utilized by the oceanographic community to return data in near real-time as part of long-term moored efforts. However, these systems are limited in data throughput per day, and lag behind the sensor and data system capability to collect and process data as part of multi-disciplinary programs. To be useful to a variety of users with the governmental focus on sharing data, distributed data base management systems need to be utilized. As part of the GLOBEC program, a modified JGOFS system has been implemented, but the effort to get the data on-line in near-real time exceeds program resources. A subset of the moored data has been available via ARGOS daily, to aid in alerting investigators of intrusive water events that are then sampled by fast response hydrographic surveys.

To improve telemetry capability in greatly increased capacity (1 MByte/day), and to provide two-way telemetry capability, spread spectrum and cellular phone have proven reliable over short, line-of-site ranges. To extend this capability worldwide, a prototype system has been constructed and tested utilizing Low Earth Orbiting (LEO)satellites that provide 9600-baud capability. Preliminary tests with one satellite have shown numerous limitations that have reduced the theoretical telemetry capability, but still showed that it is a very viable candidate for the next generation of remote buoy controlling and data collection systems.