Proceedings Of The Marine

SUM 2015

Proceedings magazine is a communication tool for the Coast Guard's Marine Safety & Security Council. Each quarterly magazine focuses on a specific theme of interest to the marine industry.

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41 Summer 2015 Proceedings The Radio Technical Commission for Maritime Ser- vices contributes to e-Navigation and supports the U.S. e-Navigation strategy as a standards developer, with a focus on integrating navigational and communica- tions functions that have traditionally been performed separately. RTCM builds on the international standards framework and will develop standards that address any gaps, particularly as they apply to smaller ships and boats. Building Upon AIS AIS units are designed with specialized navigation and binary messages and are capable of providing mariners with ATON report messages, maritime safety informa- tion, as well as meteorological, environmental, hydro- logical, and hydrographic data. Yet, this data must share AIS radio frequency channels with thousands of shipboard AIS units, causing excessive loading on these channels in many areas of the world. The RTCM has recognized this limitation and is working with industry partners to develop a broadband communi- cations "front end" — the VHF Data Exchange System — to provide new radio frequency channels with an available capacity many times that of the current AIS channels. At some point in the future, this system may access satellites capable of high data capacity in areas without an installed shore-based infrastructure, such as the Arctic. How soon before this technology becomes available? First, the International Telecommunication Union must allocate the necessary radio frequencies. This could happen as early as the World Radio Conference in November 2015. However, since it is unlikely that the IMO will require ship operators to upgrade their existing AIS units to VDES, mariners would likely need to wait until ship operators routinely replace the existing AIS units with newer VDES units. That said, the possibility of real-time chart updates and other graphical navigational and meteorological information and warnings may drive this technology to be available sooner. About the authors: Ms. Sandra Borden is media chair for RTCM's board of directors. Mr. Ed Gilbert is president of Gilbert & Associates Inc. Mr. Joe Hersey is secretary to the U.S. National Committee Technical Advisory Group to IEC TC80. Mr. Ross Norsworthy is president of REC Inc. Mr. Rudy Peschel and Mr. Joe Ryan are independent consultants. Mr. Robert Markle is the president of the Radio Technical Commission for Maritime Services. Endnotes: 1. Sherman is sighted. San Francisco Examiner, August 23, 1899. 2. In those days post and telegraph/telephone systems were government-owned in many countries and their governments invested in INMARSAT. 3. IMO standardized electronic charting technology, including its use in conjunc- tion with radar, (in Res. A.817(19)), International Hydrographic Organization (in special publications S-52 and S-57), and IEC (in publication 61174) for Electronic Chart Display and Information Systems (ECDIS), and later IALA adopted it for VTS (in Rec. V-128). IMO standardized AIS (in Annex 3 to Res. MSC.74(69)), ITU (in Rec. ITU-R M.1371), and IEC (in publication 61993-2), and later IALA adopted it for VTS (in Rec. V-128). IALA later adopted integrated environmental sensors for VTS (in Rec. V-128). IMO has since recognized the concept as navigation-related information to be provided to ships by shore side services and is codifed in an AIS Application-specifc Message (ASM) (in SN.1/Circ.289). 4. All ships of 300 gross tons tonnage and upwards engaged on international voy- ages, all cargo ships of 500 gross tons tonnage and upwards, and all passenger ships were required to ft AIS no later than December 31, 2004. SOLAS, Chapter V, Regulation 19. When a radar signal hits a radar SART, the transponder sends a signal that is received by the interrogating radar (along with the returned radar signal), which provides the radar signal processor with additional information, allowing it to enhance the return signal by producing a line of dots in the radar video image that points to the direction of the SART. In generally, a radar SART's signal can be received and processed from several miles away. The proposal to use of AIS as an alternative to the 121.5 MHz EPIRB Homing Signal has been considered by IMO, but it has not been adopted due to concerns raised by some administrations that few aircraft were equipped to home on the AIS signal. 5. 6. Maritime Administration, Military Sealift Command, U.N. Food and Agriculture Organization, and U.S. Coast Guard 2013 Recreational Boating statistics. 7. See This technical chart shows how ships would send and receive broadband naviga- tion data to and from base stations and satellites. Source IALA, ITU, and VDES developers. In this screen capture from the Coast Guard Cutter Mackinaw's ECDIS. VDES might provide the means to ensure that these charts are always up to date. U.S. Coast Guard photo.

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