How to correctly understand electronic charts

Electronic Chart Display and Information System (ECDIS) is another major technological revolution of ship navigation after radar /ARPA, and has developed into a new type of ship navigation system and decision-making assistant system. It can not only give the position of the ship continuously, but also provide all kinds of information related to navigation, and effectively prevent all kinds of dangers. At present, there are more than 200,000 ships with electronic charts installed in the world. With the gradual completion of official electronic nautical charts (ENC) in various countries, the appearance of standard ECDIS and the approval of IMO, ECDIS will completely replace paper nautical charts in the next 10 year, and become a comprehensive means of processing navigation information in 2 1 century.

The reason why electronic chart attracts much attention is that it has incomparable advantages over traditional paper chart. The electronic chart system can carry out automatic route design, course track monitoring, automatic storage of ship tracks, historical voyage reappearance, and automatic navigation alarm (such as yaw and mistaken entry into dangerous areas). ), quickly query all kinds of information (such as hydrology, ports, tides, currents, etc. ), real-time display of ship dynamics (such as refreshing ship position, speed, course, etc. Every second), and the echo image of radar /ARPA is superimposed on the chart.

Development background and basic composition

The development of electronic chart has roughly gone through three stages: 1) paper chart equivalence, from the end of 1970 to 1984. People mainly want to reduce the size and reduce the labor intensity of chart operation, so they just digitize paper charts and store them in computers. 2) In the functional development stage, by 1986, people began to tap the potential of electronic charts. Such as displaying ship position and route design on electronic chart, displaying ship parameters such as ship speed and course, giving an alarm, etc. 3) In the stage of navigation information system, electronic chart is the core of navigation information, including the improvement of electronic chart database, interface and combination with radar, locator, log, sounder, GPS, VTS, AIS and other equipment and systems. Multifunctional marine electronic chart system has played an important role in ensuring navigation safety, and has been recognized by IMO, IHO (International Hydrographic Organization) and many navigation experts. 1In July 1986, IMO and IHO established the ECDIS coordination group, and various ECDIS standards and specifications were continuously established and improved, and various ECDIS products with excellent performance were continuously introduced.

Electronic chart system consists of four basic parts: main computer system, electronic chart database, input sensor and output terminal equipment. The main computer is the core of electronic chart, which needs to be used to complete a lot of calculations and logical reasoning, and is very important for the processing of computer graphics. Electronic Navigation Chart (ENC) is officially authorized to be published. ECDIS can not only display accurate electronic charts, but also display the information of ship's position, speed, course and surrounding targets. Therefore, the system needs to connect various navigation sensors and other information sensors.

The terminal equipment of the system includes graphic display, printer and track recorder. The chart navigation element data, man-machine conversation content, alarm information, hot keys and menus shall be displayed or output for the crew to operate.

Development trend of electronic chart display and information system

At present, the performance standard, chart display specification and data standard of ECDIS have been established, paving the way for its legalization and popularization. The key problems to be solved in the future are: to establish a global electronic chart and chart correction service network as soon as possible; Expand the standard function of electronic chart system and make it intelligent; It integrates high-precision positioning system, radar collision avoidance system, ship communication system and steering control system. , to assist the decision-making of ship operation, at the same time, it can control the ship to sail on the optimal route in the most economical way and improve the shipping efficiency.

At present, some marine technology development companies in the world have connected their ECDIS with navigation system, ARPA, autopilot and so on, forming a so-called combined ship-bridge system. Its main idea is to comprehensively process the information from these navigation instruments, and provide an integrated information environment for seafarers, so that they can make decisions on ship operation quickly and improve the safety of navigation. It has become a topic of concern in maritime circles to let machines replace seafarers to complete this work, so as to reduce the possibility of shipwrecks caused by human factors and reduce the crew quota.

Electronic chart system can realize navigation of inland river ships. Because of the particularity of inland navigation environment, the requirement for positioning is higher, especially in navigation areas such as sluice area, bridge area and narrow river section. On the premise of high-precision DGPS and dynamic electronic Jiang Tu, high-precision and high-reliability navigation of inland waterway can be realized, thus bringing considerable economic benefits in safety, dredging and waterway management.