Oceans of Tomorrow sensor interoperability for in-situ ocean monitoring

The Oceans of Tomorrow (OoT) projects, funded by the European Commission's FP7 program, are developing a new generation of sensors supporting physical, biogeochemical and biological oceanographic monitoring. The sensors range from acoustic to optical fluorometers to labs on a chip. The result is that the outputs are diverse in a variety of formats and communication methodologies. The interfaces with platforms such as floats, gliders and cable observatories are each different. Thus, sensor "drivers" have to be built for each kind of sensor interface, which leads to extensive efforts in developing large-scale systems and additional fielding cost. Since the price of sensor devices is expected to decrease rapidly, these adaption efforts become the key cost factor in large-scale sensor network systems. At the other end, from a system perspective, the data transmission and visualization must be individually tailored. When multi-sensors are making measurements, the challenge of interoperability is compounded. The Oceans of Tomorrow projects are addressing interoperability in the complete data flow from sensor to user. Selected innovations at the sensor end are through implementation of the OGC PUCK protocol [PUCK web reference, O'Reilly 2006]. PUCK provides a protocol and "container" to store instrument-related information ("payload") with the instrument itself. An observing system retrieves and utilizes information through instrument's serial interface. PUCK protocol was developed by MBARI and its use is expanding [Toma 2014]. For the information flow from platform to user, an approach is the use of Sensor Observation Service (SOS), which acts as a common interface to observation data stores. For transmitting collected data from platforms to such an observation data store, the transactional and resultant handling operations of the SOS interface are used which allow the insertion/publication of measurements as well as corresponding metadata. Common SWE templates and profiles (e.g. for OGC SensorML, OGC Observations and Measurements and OGC SOS) are being used. These will be comprehensive data flow descriptions for the Oceans of Tomorrow sensors and are being created through the OoT projects in order to increase interoperability. In addition to information flow described above, further work is necessary for a common visualization and means of sharing data that can support multiple sensor types and enable overlay of observation data. The visualization will need to