Technology Testbeds

Each of these aspects can be difficult and expensive to address. Consider cellular phones. Perhaps you have tried using a cell phone in rural America. Sometimes it will work, depending on where the nearest tower is, but often you will have no reception whatsoever. Now imagine you are 50 miles offshore... the likelihood that you will be able to communicate with the shore is slim at best. Suppose you have to send data from 10 sensors every hour with no loss in data. SEACOOS will be testing a number of new technologies so that we can work towards enhancing the reliability and versatility of observing networks all around the country.

HF Radar

High Frequency Radar is used to measure surface currents in the ocean. Although the basic technology behind HF Radar has been used in ocean applications for over 20 years, significant improvements in the technology have occurred within the past 10 years. SEACOOS is focussing on two types of radar systems as permanent deployments. One is produced by SeaSonde and is a direction-finding system. The other is produced at the University of Hamburg in Germany, a WERA, that is a beam-forming system. Both types of systems may have the ablity to track vessels (in development) and provide some information on the directional wave field.

Currently two permanent HF Radar systems have been deployed: one system on the west Florida Shelf (see USF's HF Radar Page); the other on the Outer Banks of North Carolina (see UNC-CH's HF Radar Page). These systems are both generating near real-time current maps using the SeaSonde Long Range systems. University of Miami has recently completed a temporary deployment of their WERA system (see UMiami's HF Radar Page). A comparison with ADCP current data has already been made for the WERA deployment, and there is a nice animation of currents after the passage of tropical storm Henri.

Observations from SEACOOS HF radar have already produced results.

Iridium Satellite Modem

How to get data back to shore in real-time is a key issue for any long-term offshore deployment. One tool that is being tested in the region is the Iridium satelite network. With Iridium modems it is possible to send data over long distances using only a small amount of power. We seek to answer questions about the reliability of connections, and the feasibility of using this on different platforms. SEACOOS is one of a number of groups testing the Iridium system for Ocean.US. SEACOOS hosts Georidium: The Geophysical Sciences Iridium Telemetry Special Interest Group, the center of collaboration among these groups.

Lithium Solid Polymer Batteries

Power systems also provide an interesting challenge in long-term offshore deployments. Several of our observing platforms rely exclusively on solar and wind power to keep the system operational. To ensure that the power source does not go down requires an extensive bank of batteries. Essentially all marine grade batteries are lead acid, like a car battery (although deep cell absorbed glass matt batteries have some significant advantages over traditional lead acid batteries). This would not be a problem, except that lead acid batteries have a relatively low charge density, which means that in order to support a power system like these, it requires many large, very heavy batteries. SEACOOS will be testing a newer type of battery technology, lithium solid polymers, similar to what are used in cell phones and laptops. The charge density of this material is approximately 10 times that of lead acid batteries. If robust in marine environments the lithium solid polymers may provide a lightweight alternative.