13 th AGILE International Conference on Geographic Information Science 2010 Page 1 of 9 Guimarães, Portugal GINISSENSE - Applying OGC Sensor Web Enablement Natasa Veljkovic, Sanja Bogdanovic-Dinic, Leonid Stoimenov Faculty of Electronic Engineering, University of Nis INTRODUCTION In recent years, the Sensor Web concept has been significantly explored and many of its applications related to environmental protection have been proposed. Open Geospatial Consortium (OGC) has certainly had the most important role in promoting Sensor Web. The OGC Sensor Web Enablement working group has published a set of specifications named Sensor Web Enablement (SWE) (Simonis, 2008), which fully describe all key components that a Sensor Web based system should implement. The group is constantly working on further improvements of SWE, enabling companies which are working on development of the proposed services, to register and publish their achievements on the OGC Web site. The Sensor Web system implies collecting real time data from heterogeneous and distributed sensor networks and delivering it to the intelligent system components where it is correlated in order to produce new knowledge that can help make new decisions in the future. Sensor technology has significantly improved during the last few years. Sensors are smaller, more reliable, energy efficient, applicable in various environments and also less expensive. They can be placed anywhere and can measure any type of data, making it easier to monitor the environment and to respond in time when a threat appears. Thus, delivering measured values to the operator on time is very important. SWE proposes Sensor Alert Service (SAS) as a service responsible for collecting data from sensors and delivering it to the subscribed users, and Web Notification Service (WNS) as a service responsible for delivering notifications to the registered users. Together, these two services make an excellent alert- delivering system. This paper deals with implementation of these two services and their application in monitoring and notifying users about sensor events within the GINISSENSE system (Markovic et al., 2009). The rest of the paper is organized as follows: The second chapter refers to related work. The third chapter is about the GINISSENSE SWE architecture. The fourth chapter describes SAS and WNS, followed by the description of their implementation given in the fifth chapter. The last chapter describes implementation of the GINISSENSE SWE Client. RELATED WORK There are several groups currently working towards developing a Sensor Web framework for delivery of physical sensed data. Microsoft Research group has developed the SenseWeb system (Santanche et al., 2006) which provides common platform and set of tools for data owners to easily publish their data and users to make useful queries over the live data sources. GeoSWIFT (Liang et al., 2004) is a framework capable of communicating with webcams as its sensing medium and does include data storage capabilities in the form of registry service. Besides these two, there are many other groups, whose research is based on OGC SWE specifications. The official OGC Web site enables registration and review of companies working on implementing or that have already implemented some of the SWE services. Figure 1 shows comparative review of registered SAS and WNS implementations, emphasizing some important characteristics. As it can be seen, currently, there are only two complete implementations of SAS (1st Spatial Group and 52°North) and one implementation of WNS (52°North), while other implementations are still in progress. Precisely for these reasons, there is no detailed information about the work of these two companies.