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GPS detection of OCS? |
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alstorer
Really should get out more Joined: 02 Aug 07 Location: Cambridge Online Status: Offline Posts: 2899 |
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Topic: GPS detection of OCS? Posted: 07 Dec 13 at 8:27am |
from the sailing watch thread
How do you propose squaring the definition of OCS (and finishing, as the same could give you finish times) with a wrist mounted unit? Or change it, so that OCS is the mast and require a mas mounted unit? Requiring a bow mounted unit would cause all sorts of definition and mounting problems with boat design, especially on anything with a bowsprit that launches through a snout Edited by alstorer - 07 Dec 13 at 8:27am |
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Al |
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yellowwelly
Really should get out more Joined: 24 May 13 Online Status: Offline Posts: 2003 |
Post Options Quote Reply Posted: 07 Dec 13 at 8:34am |
Is GPS accurate enough?
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Brass
Really should get out more Joined: 24 Mar 08 Location: Australia Online Status: Offline Posts: 1146 |
Post Options Quote Reply Posted: 07 Dec 13 at 9:16am |
You may be aware ISAF Racing Rules Committee is running a Subcommittee investigating GPS/sensors for OCS.
I understand that the positioning problem is addressed by measuring-in the sensor unit, then calculating an offset to the end of the bow, and possibly some sort of offset to allow for B-max. Problem with dinghies would be that that approach wouldn't cover hiking positions of crew, especially trapeze. Definition of start could be changed (by ISAF, not SI, cos SI cannot change Definitions), but you would need to be careful that you didn't come up with a definition that suited GPS/computers but did not suit mark one eyeball. |
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Rupert
Really should get out more Joined: 11 Aug 04 Location: Whitefriars sc Online Status: Offline Posts: 8956 |
Post Options Quote Reply Posted: 07 Dec 13 at 9:48am |
I'm guessing that the Mk1 eyeball can, on most club startlines, tell to just a few inches whether a bow is over the line. I can't see GPS managing that at all.
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Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6649 |
Post Options Quote Reply Posted: 07 Dec 13 at 9:58am |
I was very much thinking on my feet... Agree about disqdvqntages of position etc, but I was mostly thinking about the communications aspect. Remember it doesn't have to be perfect, merely no worse than the current system. A mast base mounted transponder and offset probably works for one designs.
I imagine RRS changes would be needed, quite likely one that gave alternative definition of start for controlled races. Edited by JimC - 07 Dec 13 at 12:04pm |
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Lukepiewalker
Really should get out more Joined: 24 May 06 Location: United Kingdom Online Status: Offline Posts: 1340 |
Post Options Quote Reply Posted: 07 Dec 13 at 11:57am |
It's a dream wishlist, we're not proposing anything...
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Ex-Finn GBR533 "Pie Hard"
Ex-National 12 3253 "Seawitch" Ex-National 12 2961 "Curved Air" Ex-Mirror 59096 "Voodoo Chile" |
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alstorer
Really should get out more Joined: 02 Aug 07 Location: Cambridge Online Status: Offline Posts: 2899 |
Post Options Quote Reply Posted: 08 Dec 13 at 10:07pm |
I appreciate it was an off-the-cuff suggestion. But it's one that merits some investigation. Could have some sort of hybrid system combining transponders on the committee boat and pin-end mark with GPS
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Al |
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craiggo
Really should get out more Joined: 01 Apr 04 Location: United Kingdom Online Status: Offline Posts: 1810 |
Post Options Quote Reply Posted: 08 Dec 13 at 10:13pm |
Not sure if GPS is accurate to that level.
Could use a high speed camera and a Matlab script to check the image and determine who was over the line. |
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Rupert
Really should get out more Joined: 11 Aug 04 Location: Whitefriars sc Online Status: Offline Posts: 8956 |
Post Options Quote Reply Posted: 08 Dec 13 at 10:59pm |
I prefer the idea of a high powered rifle set about 6" above the water. Any boats with holes in the bow were over. Any helms with extra holes in the bum were a long way over.
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Firefly 2324, Puffin 229, Minisail 3446 Mirror 70686
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6649 |
Post Options Quote Reply Posted: 09 Dec 13 at 5:00am |
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