Correct Understanding Of Electronic Chart

Electronic Chart Display and Information System ECDIS is another great technological revolution in ship navigation after radar/ARPA. It has developed into a new type of ship navigation system and auxiliary decision-making system. It can not only give the ship's position continuously, but also provide various information related to navigation, effectively preventing various dangerous situations. At present, there are more than 200,000 ships installed with electronic charts in the world. With the gradual completion of official electronic charts ENC of various countries, the emergence of standard ECDIS and the recognition of IMO, ECDIS will completely replace paper charts in the next 10 years and become a comprehensive means of processing maritime information in the 21st century.


    Electronic charts have attracted great attention because they have advantages that traditional paper charts cannot match. The electronic chart system can perform automatic route design, heading and track monitoring, automatic storage of own ship's track, historical voyage re-demonstration, automatic navigation alert such as yaw, stray entry into dangerous zone, etc.), and quick query of various information (such as hydrology, Ports, tides, ocean currents, etc.), real-time display of ship dynamics (such as refreshing ship position, speed, heading, etc.), overlay radar/ARPA echo images on the chart, automatic correction of thousands of charts only needs A few minutes.


    Development background and basic composition


    The development of electronic charts has roughly gone through three stages: 1 The equivalent of paper charts. From the late 1970s to 1984, people mainly wanted to reduce the volume and reduce the labor intensity of chart operations. Therefore, only the paper The nautical chart is digitally processed and stored in the computer. 2 The functional development stage. By 1986, people began to tap the various potentials of electronic charts. Such as displaying ship position and route design on electronic charts, displaying ship parameters such as ship speed and course, alarms, etc. 3) At the stage of navigation information system, the electronic chart is used as the core of navigation information, including the improvement of electronic chart database, and the integration of radar, locator, log, depth sounder, GPS, VTS, AIS and other equipment and systems. Interface and combination etc. The important role of the multi-functional marine electronic chart system in ensuring the safety of ships has been recognized by IMO, IHO (International Hydrographic Organization) and many maritime experts. In July 1986, the IMO and IHO established the ECDIS coordination group. Various standards and specifications of ECDIS have been continuously established and improved, and various ECDIS products with excellent performance have been continuously introduced.


    ECDIS is composed of four basic parts: the main computer system, electronic chart database, input sensors, and output terminal equipment. The main computer is the core of the electronic chart, it needs to be used to complete a large number of calculations, logical reasoning, and the most important point is the processing of computer graphics. The electronic navigation chart ENC is issued under official authorization. In addition to displaying accurate electronic charts, ECDIS should also display information about the ship’s position, speed, course and surrounding targets. Therefore, the system needs to be connected to various navigation sensors and other information sensors.


    The system terminal equipment includes graphic displays, printers, and track recorders. It should display or output the data of various navigational elements of the nautical chart, the content of man-machine dialogue, alarm information, hot keys and menus for navigators to operate.


    Development Trend of Electronic Chart Display and Information System


    At present, ECDIS's performance standards, chart display standards, and data standards have all been established, paving the way for its legalization and popularization. The key issue to be solved in the future is to establish a global ENC and chart correction service network as soon as possible; expand the standard functions of ECDIS to make it intelligent; the same as the high-precision positioning system, radar collision avoidance system, and ship communication system , The rudder control system, etc. are integrated to assist in making ship handling decisions. At the same time, it can control the ship to navigate the optimal route in the most economical way and improve shipping efficiency.  


    At present, some maritime technology development companies in the world have connected their ECDIS with navigation systems, ARPA, autopilots, etc. to form the so-called combined ship bridge system. The main idea is to comprehensively process the information from these navigational instruments, and provide an integrated information environment for the navigators, so that they can quickly make ship handling decisions and improve the safety of navigation. Let the machine replace the navigator to complete this work, in order to reduce the possibility of human factors causing marine accidents and reduce the crew quota, which has become a topic of concern in the maritime industry.


    ECDIS can realize ship navigation in inland waterways. Due to the particularity of the inland navigation environment, the requirements for positioning are higher, especially in navigation areas such as gate areas, bridge areas, and narrow river sections. Under the premise of high-precision DGPS and dynamic electronic river maps, inland waterways can be used. Realize high-precision and high-reliability navigation, which brings considerable economic benefits in terms of safety, dredging, and channel management.