Web-based GIS dedicated for marine environment surveillance and monitoring

摘要

Maritime and port areas throughout the world are exposed to many different hazards, like pollution, terrorism and natural disasters. Early detection, identification and preparation of appropriate response strategies is especially important in the case of semi-enclosed Basins like the Southern Baltic Sea, mainly due to the marine ecosystems' continuous absorption of pollutants including oil, heavy metals and chemicals. Many of those agents are characterised by great toxicity and cause devastation of the natural environment. The recent development in the information technology provides the means and possibilities for much faster and more efficient access to survey data, allowing their remote, nearly real-time management, processing and visualisation. Several approaches and techniques of measurements are available in marine environment monitoring. These consist of direct sampling, airborne and satellite imagery, hydrological measurements using CTD probes, remote sensing with the use of electromagnetic waves, acoustic methods based on the data acquired by multi-beam and side-scan sonars and single-beam echosounders. The acquisition, processing, integration and visualisation of various kinds of data constitutes an important problem in the context of development of applications supporting littoral environment management. These methods are not easily suited for monitoring threat levels for maritime Critical Infrastructures (CI) like ports and shipyards. However, this field has also been explored, using specialised modules like CARVER2 or similar systems now easily available not only commercially. The presented system integrates data from all of the aforementioned sources as well as others, like live radar feed and oil spill spread simulation results. The data from the investigated marine region is presented in the form of multiple, time-varying layers, rendered in up to three dimensions. The system allows authenticated end users to remotely view these layers in a geographic context while also providing interactive features like oil spill spread animation and tools for layer query. The CI threat sensing element of the system is being developed in cooperation with the City of Gdansk. The system's application for monitoring water pollution as well as processing, integration and visualsation of various kinds of background and sensor data has been reported recently. The presented system consists of several modules, or subsystems, namely the Data Integration and Adaptation module, the Remotely Accessible GIS and third-party simulation engines, connected through the interface for Simulation Modules. The Data Integration and Adaptation module is developed using the Microsoft .NET platform and the ESRI ArcGIS Engine, which is a set of GIS objects with application programming interfaces (APIs) for COM, .NET, Java, and C++. To provide a common and efficient solution for geospatial data serving via the TCP/IP protocol, the system utilises the ArcSDE application server that facilitates storing and managing spatial data (raster, vector, and survey) in an underlying database. ArcGIS Engine MapControl and GlobeControl components provide a standard set of GIS functionalities like map viewing, zooming and panning for two-dimensional and three-dimensional imaging respectively. Interfaces to various external sensors were implemented during the development of the system. The Web-GIS module was developed entirely with the use of Open-Source technology. It utilizes the established GeoServer technology for serving Open Geospatial Consortium's (OGC) standard Web Map Service (WMS) layers and Apache Web Server as the HTTP proxy. Data processing is done by means of custom Java 2 Platform Standard Edition servlets running within the Tomcat Servlet Engine. The browser-independent DHTML client is built with help of the OpenLayers Javascript library. The Interface for Simulation Modules allows third-party applications to provide data directly into the Spatial data