| With the continuous development of inland shipping industry in China, the number of inbound and outbound ships and the density of ships in port as well as the navigation marks are increasing, which reduces to increasingly severe safety issues of navigation. Therefore, the management of inland waterways and shipping companies has an urgent need to keep aware of real-time status of ships and the navigation lights in respect to provide strong service and support for safe navigation of the ships. Obviously,electronic channel chart, as the core component of intelligent navigation and electronic channel, represents superiority in monitoring the ships in port and navigation marks in channel increasingly. Therefore, to produce standard electronic channel charts rapidly and accurately in order to meet the needs of the community is a problem to be solved.At the beginning of 2015, Yangtze River Waterway electronic mapping system was put into operation after five years’ research and development. It is able to provide various, practical guide (help) navigation services and management functions for the end-users (public and Shipping Companies, etc.) and aviation management through electronic mapping system. However, since the Chart aimed at main waters in Yangtze River without consideration of its, such as the Han River and Jialing River, Yalong, Wujiang and Yuanjiang and so on. As a result, Yangtze River Waterway Bureau encourages and supports the aviation-related management of tributaries to do independent research and development of regional channel chart abide by Yangtze regulations which can be applied in corresponding channel management systems in order that the tributaries can be fully utilized.Han River, as the longest tributary of Yangtze River, with total length of 1577 km, basin area of 159,000 square kilometers and abundant rapids, canyon, big runoff volume, wealthy water resources, is with good navigation conditions. Therefore, in order to take full advantage of its navigation conditions and to create a dedicated intelligent shipping, electronic channel, Hubei Co., Ltd. Lan Yu beacon sponsored and joint Yangtze University professors to develop intelligent electronic Han River Waterway Management System at the end of 2011.Meanwhile,70 kilometers of the Han River from Hanchuan to Caidian was used to research and produce the electronic channel chart. The author of this paper was mainly responsible for the project. After research of a year and a half, a production method and process was proposed to build an electronic channel chart ultimately in June 2013, based on which an electronic channel chart of 70 kilometers from Hanchuan to Caidian was produced.However, with the continuous promotion and application of electronic channel chart, the shortages of original mapping mode are exposed increasingly, such as too much human involvement, too much and complicated use of software,inaccurate water depth data and so on. Therefore, this paper improves and upgrades the producing method and proposed a brand new set of producing methods and procedures after analyzing and tidying the previous channel chart deeply and completely based on research of domestic and foreign norms and standards of electronic channel chart. The procedures include preprocess of data in non-standard electronic chart, removing redundant elements and marks, standardized elements and marks, the classifications of elements and marks are involved; further objects the preprocessed data which gives each element and mark properties and corresponding property values; produce same-depth data according to water depth dots, including scatter grid, triangulation, contour tracing and cropping. The standard electronic channel chart is generated according to the processed basic physical element and bathymetric data.The main contents of this paper include:research of international ECDIS standard (S-57) and domestic "Yangtze River Waterway electronic map production specifications" (CJ-57); researches of dedicated vector map formats of several common graphics editing software:dwg, dxf, shp, and directly read and write components in these file formats; research of Carnac.NET graphical development components, the design of the electronic channel chart data generation system based on the components.The data generation system supports various input and output of graphics, what’s more, the feature is the editing functions of channel chart, such as:rapid extraction of space objects from other layers, merge of space objects, optimize of space object, specifying feature data to space objects and so on. The system is divided into two separate parts, electronic channel chart data preprocessing software and electronic channel chart generation software, where the former aimed mainly to complete the generation of static subject mark, while the dynamic elements (river depth point based on river depth point data, contour, and other deep-face) are completed through the channel map generation software. These elements were based on river depth point data, using the triangular grid technology to generate depth contour, then fill the polygons caused by the lines, and then cut the depth contour and polygons according to the picture border to generate dynamic elements and marks. Then write these static and dynamic elements to channel chart file (.000) according to CJ-57 standard.The innovation of this paper is to propose a framework for an electronic channel chart generation tools, and generate electronic channel chart data generation system in accordance with the framework. The system overcomes the shortages of manual work and continuous switch between different editing software in previous methods and processes, optimizing and upgrading the algorithm of producing depth contour and area to cope with complex terrain. The new mapping method greatly simplifies the data process and shortens the cycle of drawing. Han River electronic channel chart generated based on this method has been applied in practical projects, and has achieved good results. |
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