A Flexible Data and Sensor Planning Service for Virtual Sensors Based on Web Service

How to achieve a flexible data and sensor planning service to schedule, plan, and empower diverse sensors and heterogeneous data ordering systems is a big challenge. In this paper, a service-oriented framework of data and sensor planning service for virtual sensors is proposed. The framework includes an Open Geospatial Consortium (OGC)-compliant Sensor Planning Service (SPS), a Web Notification Service (WNS), a Sensor Observation Service (SOS), and virtual sensors. There are two important key technologies in this framework, namely a flexible SPS middleware and an asynchronous message notification mechanism. The flexible SPS middleware, based on a configuration file and standard interfaces, is adopted to integrate virtual sensors into a sensor Web. A WNS-based asynchronous notification middleware is used to inform the user of the status of a task that may need midterm or long-term actions. The framework has been successfully demonstrated in application scenarios for Simplified General Perturbations Satellite Orbit Model 4 (SGP4) and Earth Observation System ClearingHOuse (ECHO). The results show that the proposed method has the following improvements over the existing SPS implementation: a uniform planning service for more satellites, a seamless connection with data order systems, and a flexible service-oriented framework for virtual sensors.