Oak Ridge National Laboratory Leads National Effort for Sensor Web Interoperability

Author: Frank DeNap, Manager
SensorNet Program
Oak Ridge National Laboratory (ORNL)
P.O. Box 2008
Oak Ridge, TN 37831
email: denapfa@ornl.gov

The National Center for Sensor Systems Interoperability (NCSSI) at Oak Ridge National Laboratory (ORNL), along with the National Oceanic and Atmospheric Administration (NOAA), other federal laboratories, universities and private sector partners, is designing and developing SensorNet. SensorNet is a vendor-neutral, evolutionary interoperability framework for web-based discovery, access, control, integration, analysis, exploitation and visualization of multiple online sensors, transducers, sensor-derived data repositories, and sensor-related processing capabilities. The purpose of SensorNet is to provide a comprehensive nationwide system for real-time detection, identification, and assessment of chemical, biological, radiological, nuclear, and explosive hazards. It provides distributed access with multi-level security, information fusion, and common operational picture.

Part of the SensorNet project is deploying a variety of sensors at strategic locations such as military installations, traffic control points, and truck weighing stations. The sensors will be connected by secure and redundant communication channels to local, regional and national operations centers. Automated predictive plume modeling will provide rapid assessments of the direction and impact of toxic airborne releases. The goal is a national system for comprehensive incident management in cooperation with state and local governments.

From a national security perspective, SensorNet addresses the problem of stovepipe sensor networks, incompatible sensor standards, lack of real-time availability of data, and lack of common and consistent schemas for sensor description, control and data. The goal is to save lives in the event of an emergency event or a terrorist attack. Homeland Security is the particular focus, but the same issues apply to other government domains and to commerce and research. ORNL has joined the Open Geospatial Consortium (OGC) to support the OGC Sensor Web Enablement (SWE) interoperability standards effort and to be sure SWE standards are aligned with SensorNet requirements.

SensorNet planners began following the OGC's work early on. Every sensor has a location and provides measurements with a geospatial component. Therefore, standards must be part of an interoperability framework for sensors. The sensor interface standards approach in the OGC is compatible with the network centric data services environment and service oriented national architecture NCSSI is developing. By developing sensor interface, schema and encoding standards that are consistent with this framework, OGC members are making it possible for measurements at known locations – either dynamic or in-situ - to be used in decision making of many kinds.

As part of their development process, the SensorNet team uses "operational prototyping" activities in which users tell them honestly how well the experimental technology works. They run testbeds to try out different kinds of queries for different kinds of applications and to learn things like what services need to exist, how to store the data, and how to parse a SensorML¹ document to get real-time performance. Existing user testbeds are important. For example, at Fort Bragg, the "City of Fort Bragg" has an integrated sensor management center. Sensor types range from fire alarms to anti-intrusion sensors on arms rooms to EPA sensors for the engineering group. All the sensors are accessible in an integrated incident management center that provides total installation awareness, like a finger on the pulse of the city.
¹SensorML (Sensor Model Language) is an OGC recommendation paper.

NCSSI was an early adopter of the OGC SWE specifications even while these schemas and service definitions were still in early stages of development. Several of the OGC SWE specifications were incorporated early within the SensorNet design and implementation. NCSSI is now working with Dr. Mike Botts, the Chair of the SWE Working Group and the principal author of SensorML, to determine how to best utilize SensorML and other the SWE specifications to meet the needs of the SensorNet. In addition, as an active member of OGC, ORNL is bringing important requirements into the OGC SWE program and helping to mature the OGC SWE specifications. As part of this role, for instance, ORNL is serving as the catalyst for the complementary blending of SensorML and the IEEE P1451 standard for "plug-n-play" sensors, as well as helping mature the Sensor Alert Service through the use of existing standards, such as the OASIS Common Alert Protocol (CAP).

ORNL will be a major sponsor of the OGC's Emerging Technology Summit on SWE which will be held in the Washington, D.C. area in April.

ORNL and other OGC members will sponsor an OGC testbed activity, the OGC Web Services, Phase 3 (OWS3). A major portion of OWS3 will be Sensor Web Enablement. OWS3/SWE will demonstrate the transformation of raw sensor data into feature-oriented "Observations" accessible through web services. OGC Observations are semantic objects consisting of measurements at a location. Web services provide a level of service interoperability not currently available for network connected sensors. A key element of OWS3 will be SensorML. OWS3 will develop methods for sensor descriptions in the hardware-oriented IEEE 1451 to be available in web-oriented SensorML. IEEE1451 sensors will be made available as web services using an OGC Sensor Observation Service. The OWS3 SWE activities will contribute to the technology needed to make millions of sensors available as web services, thereby greatly expanding the availability and applicability of the sensor observations.

John Strand directed the SensorNet project from inception to a recent transfer of management to Frank DeNap. Both have extensive development and executive backgrounds in telecommunications. "When the telecommunications industry picks a standard and adheres to it," John explains, "it allows things to work internationally. A cell phone user in New York City can call someone on an autobahn in Germany. A call spans multiple networks. Standards enable this kind of interoperability. It would be a shame if we didn't get national and global input and buy-in on standards for sensor webs for hazard detection. But the goal of standards is not only to make a national or global system possible. Having a modular and open system architecture for hardware, software and communications allows for a choice of commercial off-the-shelf products and future seamless upgrading of the system. Also, adherence to an open, common architecture will result in ongoing competitive development of new technologies that will improve SensorNet and that will also find other uses globally."

The development of these technologies will enhance economic growth and enhance airborne hazard protection, and it will also enhance weather analysis and prediction, traffic control, aircraft surveillance, inventory tracking, earthquake monitoring, and environmental management worldwide. SensorNet benefits from making the global sensor systems industry as good as it can possibly be. For this reason, the organizations that are building SensorNet hope to see increased participation in OGC by the world's sensor users and providers.