``Towards a Distributed Information System for Ocean Processes''
Prof. Nicholas M. Patrikalakis and Mr. Stephen L. Abrams
Massachusetts Institute of Technology, Department of Ocean Engineering
Cambridge, MA 02139-4307
E-mail: nmp@mit.edu, sabrams@deslab.mit.edu
URL: http://deslab.mit.edu/DesignLab/poseidon/

With the advent of new sensors, storage technologies, and networking technologies, the potential exists for a new era of ocean science investigation where students, scientists and researchers from different disciplines, and government policy makers and officials have frictionless access to oceanographic data, simulation results, and software. Our goal is to create standards and an information processing environment that allows these users to extract and employ marine data from ocean sampling sensors and the simulated ocean as timely input to visualization, analysis, and ocean modeling software. The intent of the system is to make scientific inquiry easier, quicker, and more collaborative in nature by creating an oceanographic metadata standard and a software system that uses that standard to create a frictionless simulation and analysis environment.

The premises behind this project are:

Our system will provide the oceanographic scientist, researcher, or planner with the computational infrastructure necessary for the flexible creation and execution of complex simulation and analysis workflows, whose individual components are distributed oceanographic data and software resources.

The three main research thrusts of this project are:

To facilitate the identification of and access to the appropriate resources, we will utilize a uniform marine ontology, or controlled formal vocabulary, to attach descriptive domain-specific metadata to all resources registered with the system, enabling efficient metadata-based searching for distributed data and processing systems. Our ontology and metadata efforts will draw on existing standards in the geoscientific and oceanographic fields whenever possible.

To gain widespread acceptance and effective use, and to ensure future extensibility, a distributed system must allow for the widest possible heterogeneity in its operating environment. Since each resource component of a workflow potentially exists on a unique host, it is imperative that we use a common information transport mechanism that supports transparent interoperability.

Process management encompasses the various administrative capabilities of the executive system for registering resources, attaching appropriate metadata to those resources, and generating, validating, and executing workflows. One important aspect of workflow management is automatic generalized data translation, which is necessary to ensure the smooth flow of data between the computational nodes of the workflow, regardless of syntactic and semantic mismatches between various input and output formats. Another important issue is the mechanism for smoothly integrating established legacy systems --- despite possible obsolescence of implementation environment, non-interactive execution mode, or non-network connectivity --- into the standard operating framework.

Oceanographic processes, whether physical, chemical, biological, acoustical, geological, or optical, are all characterized by a wide range of spatial and temporal scales and variability. Furthermore, these processes exhibit complex couplings and interactions. Our system will explicitly address these issues by providing an extensible computational environment for the manipulation of complex oceanographic workflows. No longer burdened with the technical minutiae of networking, distributed search and retrieval, query languages, and data management, the user of the system is freed to concentrate on domain-specific scientific research issues. By providing a mechanism for rapidly performing numerous simulation scenarios, the system will enable a more efficient and exhaustive exploration of the potential solution spaces of complex, multi-disciplinary oceanographic problems or research areas. One component of the research program concerns the investigation of multiscale, multidisciplinary ocean phenomena. Our system will, in general, facilitate the exploration of these type of complex geoscientific systems.

A detailed investigation of many interesting oceanic processes requires in situ measurements of the ocean environment. One highly effective and efficient means of utilizing sensor resources is through adaptive sampling with autonomous unmanned vehicles. Through a dynamic process of cooperative autonomous decision-making in response to changing environmental or experimental conditions, these vehicles can optimize their mission for the exploration of regions of high interest, lowering the time and expense of acquiring relevant high-quality data.

Our system will be a prototype of a domain-specific, multi-disciplinary knowledge system that addresses issues of scale, heterogeneity, and distributed interoperability of the computing environment.