Extension of Coding CEVNI Signs and Marking for European Waterways
This paper presents a new method of coding for signs and marking, which is based on the extension of signs and marking described in Annexes 7 and 8 of the European Code for Inland Waterways (CEVNI). Being members of three European expert groups, we have proposed these new codes of waterway signs and marking and recommend them for cases where they can be efficiently used. The main goal is to enable the use of these codes in databases, GIS systems and Web applications for efficient maintenance of waterway information. In addition, they will also contribute to international data exchange for creating standardised electronic messages described by ERI and NtS working groups. The intention is not to amend the existing coding from the Inland ECDIS Standard, which was developed for creation of Electronic Navigation Charts (ENCs). For example, the use of these new codes is tested through the Web GIS application for presentation of inland waterway signs and marking on the Danube River in Croatia. The application examples concern automatically generated reports on the position, characteristics and functioning of different waterway signs and river navigation marking located on the digital map.
Sharing Data among Users through Dynamic Web Applications for the River Information System
The aim of the Croatian national joint project as part of the CROatian River Infor-mation Services (CRORIS) is to develop a specialized information system for sur-veillance of the Croatian segment of the Danube River (i.e., River IS). In this paper, emphasis is placed on sharing relevant and timely information among different River IS user groups as well as on efficient data management provided by this in-formation system. For this purpose, a use case diagram of the Unified Modeling Language (UML) was created to represent the hierarchies of user groups and differ-ent applications accessed by a particular group. As an example, the Web application architecture for automatic generation of maps, diagrams and reports of water level data is shown. Application architecture is based on the three-tier client-server archi-tecture for the Web. The eXtensible Markup Language (XML) based approach using modern object technologies was applied. For presentation of the time series dia-grams, the Scalable Vector Graphic (SVG) documents were created. The concrete application example involves presentation of daily average water level data in the form of the time series diagram for the monitoring station selected on the map.
Remote Display of Hydrological Information for Danube Waterway by Automatic Processing of XML Data
Safety of inland navigation requires efficient remote processing of automatically measured hydrological and meteorological data and their display on visible devices along the fairway. A pilot project was initiated in which large electronic LED displays will be installed at bridges on Danube river in Croatia. Data from automatic water gauges will be prepared on the Web server as an XML document and extracted with additional important alarm messages into text files for transmission to remote displays. Wireless communication is performed using GSM modems or simple GPRS mobile phones. Screen capture of information displayed can be received by a remote Control Station as a raw JPG files.