Key Technologies Of Sensor Web Integration And Processing

Sensor Web is a new method for collaborative observation, information fusion, and online service of sensors in a distributed network environment. Open Geospatial Consortium (OGC) has developed Sensor Web Enablement for the specifications of information sharing and interoperation between sensors, observation source, and sensor network services. For the diverse sensors, observation data, and services, Sensor Web suffers problems that how to conveniently and dynamically obtain sensor data, effectively process data, and combine multiple services. To address these problems, a unified integration-and-processing framework and a describe model of service, as well as key technologies are proposed. The major research activities of this paper include the following:1. Research background, and review of research on Sensor Web at both home and abroad are introduced. After analyzing the existing problems, the significance of this study is put forward.2. This paper introduces the existing basis of integration and processing technology, including geographic spatial data integration and processing technology, and the Sensor Web specifications. The integrated mechanism, process, and distributed integration and processing method of geographic spatial data integration and processing technology are detailed.3. The integration-and-processing framework and the describe model of Sensor Web are proposed. The layers, protocol, function, and workflow of the integration-and-processing framework are studied. The formalization of object-oriented description model for Sensor Web is defined. The integration-and-processing method of description model is explained. The key technologies of integration-and-processing framework for Sensor Web are studied; the technologies are flexible Sensor Web service technologies, processing technologies of distributed Sensor Web data, and combining of multiple Sensor Web services. 4. The technologies of flexible Sensor Web service mainly design configurable and extendable Sensor Web services to realize the access of multiple source-data and flexible data and planning service. Flexible Sensor Web service means it is easy to develop service instance in any application/task/process and the framework itself is not changed. Develop SOS and SPS based on abstract factory pattern, and WPS with abstract rewrite method. Introduce the concept of virtual sensor. Virtual sensor is a non-entity sensor which can provide data to enrich the scope of sensor, to expand the range of applications and to help the unified integration of multi-source observations. Integrate flexible SOS and SPS to form the framework of flexible data and sensor planning service.5. Distributed sensor data processing technology can solve the problem of efficient processing in distributed Sensor Web environment. A framework of WPS coupling with a distributed processing environment is proposed. Take Apache Hadoop as an example, and illustrate the method of coupling WPS Hadoop.6. Workflow-based multi-sensor web services composition technology can solve the integration of one-stop multi-sensor web services. The combining framework of multiple Sensor Web services based on workflow is proposed. Analyze the realization of data flow in the multi-sensor web service, and the execution of workflow in execution engine, as well as the ability to integrate multi-sensor web services under different conditions.7. In order to verify the integration-and-processing framework and models of Sensor Web services, a video change detection and object tracking under Sensor Web, and dynamic crop growth monitoring experiment were designed. And these experiments are analyzed from three aspects:the design of integration framework, the implement of framework based on object model and results. The first two experiments verify flexible services, dynamic uniform access for multi-source data and the object model in integration. The last experiment verifies the coupling between WPS and distributed processing environments can achieve efficient computing. The results show that the proposed integration-and-processing framework, model and key technologies for the Sensor Web are feasible.