Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Politics : Politics for Pros- moderated -- Ignore unavailable to you. Want to Upgrade?

To: LindyBill who wrote (241471)	3/11/2008 9:21:50 PM
From: greenspirit	Respond to of 793999

Little known to most Americans is every large merchant ship in the world is tracked by the U.S. It's a daunting task that isn't 100% reliable. The worldwide AIS (Automatic Identification System) is making it easier. Within the next year or two if a ship is not participating in the system it will be considered a threat and potentially boarded. en.wikipedia.org ------------------------------------------------------------------------ What is the Automatic Identification System (AIS)? Picture a shipboard radar display, with overlaid electronic chart data, that includes a mark for every significant ship within radio range, each as desired with a velocity vector (indicating speed and heading). Each ship "mark" could reflect the actual size of the ship, with position to GPS or differential GPS accuracy. By "clicking" on a ship mark, you could learn the ship name, course and speed, classification, call sign, registration number, MMSI, and other information. Maneuvering information, closest point of approach (CPA), time to closest point of approach (TCPA) and other navigation information, more accurate and more timely than information available from an automatic radar plotting aid, could also be available. Display information previously available only to modern Vessel Traffic Service operations centers could now be available to every AIS-equipped ship. With this information, you could call any ship over VHF radiotelephone by name, rather than by "ship off my port bow" or some other imprecise means. Or you could dial it up directly using GMDSS equipment. Or you could send to the ship, or receive from it, short safety-related email messages. The AIS is a shipboard broadcast system that acts like a transponder, operating in the VHF maritime band, that is capable of handling well over 4,500 reports per minute and updates as often as every two seconds. It uses Self-Organizing Time Division Multiple Access (SOTDMA) technology to meet this high broadcast rate and ensure reliable ship-to-ship operation. navcen.uscg.gov

To: LindyBill who wrote (241471)	3/11/2008 9:48:40 PM
From: greenspirit	Read Replies (1) \| Respond to of 793999

Bill, remember the Cosco-Buson collision in San Francisco with the Bay Bridge? Here's the recorded AIS data of the collision. boatingsf.com Having read the reports in detail, the cause of the accident was the pilot and ships Captain not understanding how to read the electronic chart. So many companies have been making electronic charts in the past few years, a standard has not been enforced. So, symbols and data on the computer screen look different depending on what software you're using. A standard has been established, but not every software company is following the ECDIS format. The red ship is the Buson, they thought the bridge span marked the center of the channel and steered right for it. The radar broke just after getting underway and it was foggy so they were driving based on GPS position on the electronic chart. A more detailed graphic is here... boatingsf.com