ION Technical Content
Electronic Charts in the Nineties
| Abstract: | Electronic Charts have a long pedigree, based on literally hundreds, if not thousands of years of maritime experience. This recent development relies heavily on the microprocessor, GPS or loran, and radar. The electronic chart is unique among most technical innovations inasmuch as it is a legal document; hence it is necessary to describe the administrative and legal factors involved in its development, along with technical improvements. The administrative factors include activities on the part of the hydrographic agencies, the IMO, RTCM and IEC to write standards for ECDIS. These have resulted in provisional standards presently issued, with the issue of final documents by 1993. The (RTCM) standards encompass three classes, with the first (as is the case with IMO) designating a system that is the legal equivalent of a paper chart. Sea trials are continuing to assess the validity of these standards before final issue. Two types of chart databases are being constructed: raster scan and vector. The latter have the advantage of being able to produce a “layered” display. Differential GPS is able to provide the necessary accuracy of positioning, and loran, when radar is added to ECDIS, is also satisfactory. Radar adds value to the ECDIS display by showing images of vessels or objects in or near ownship, making visible collision possibilities and confirming the validity of the positioning system. The on-board processor for ECDIS varies from small in yacht-size track plotters to large and complex for full-compliance ECDIS. Electronic charts can be updated by radio means so that ships entering harbors can have an up-to-date chart, complete with current warnings and Notices to Mariners. ECDIS displays are similar to VTS displays, easing the problems of attaining ship control in harbors. ECDIS sea trials are continuing, with a major project to get underway in the US. Details are described of the US tests, including goals, participants, and sources of funding. ECDIS will probably be a building block towards an integrated navigation system with equipment carriage becoming mandatory. IMO will probably write new and additional standards in response to the needs of governments that wish to minimize environmental damage resulting from ship accidents, and in response to shipowners that want to reduce operating costs. |
| Published in: |
Proceedings of the 46th Annual Meeting of The Institute of Navigation (1990) June 26 - 28, 1990 Atlantic City, NJ |
| Pages: | 35 - 40 |
| Cite this article: | Updated citation: Published in NAVIGATION: Journal of the Institute of Navigation |
| Full Paper: |
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