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TL;DR: On a large cruise ship the GPS antenna broke, and the GPS continued to display plausible coordinates based on dead reckoning with only a tiny icon to ind
by tlb 12y ago
TL;DR: On a large cruise ship the GPS antenna broke, and the GPS continued to display plausible coordinates based on dead reckoning with only a tiny icon to indicate the data wasn't based on a satellite fix. The dead reckoning error accumulated to 15 miles, which drove them aground near Nantucket.
- mikepalmer 12y agoomg, spoiler alert! :-)
- walshemj 12y ago:-) One of my uncles has just retired from the main UK collage for training Merchant Marine officers - he commented that a lot of the younger officers don't have much experience of using the traditional methods of fixing your position.
- gumby 12y agoActually I think the real TL;DR is that the crew failed to "trust but verify" and that the automated cross checks were set up in such a way that they cancelled each other out. It's a cautionary tale for anyone developing self-navigating devices. Plus for me the document is cut off mid-sentence.
- URSpider94 12y agoPlus for me the document is cut off mid-sentence. It's a copy of a book chapter, plus the end notes (notice how the page number jumps near the end). The end notes aren't paginated by chapter, so you're seeing the first paragraph of the end notes for the NEXT chapter at the bottom of the page.
- URSpider94 12y agoMore than that, the dead reckoning data from the GPS "infected" numerous other automated systems that should have caught the error, because there was (is?) no defined standard for what a GPS receiver should do in the event of losing its fix. In this case, it kept transmitting position data and added a proprietary "invalid" tag that wasn't parsed by other equipment.