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Board » Technical Support » Is the DTG calculation correct

Posted by mwagg56 Posts 2 Registered at 2009-03-23 23:12:20	2009-05-22 05:03:29 - Is the DTG calculation correct
	Is it just me but does the DTG calculation seem incorrect. Seems to be too much north of the rum line!
Posted by jakob Posts 364 Registered at 2007-09-04 10:05:30	2009-05-22 05:46:31 - Re: Is the DTG calculation correct
	DTG is calculated along a great circle (shortest way) and not the along rhumb-line (constant course). ok? ...one of the guys behind the game...
Posted by mwagg56 Posts 2 Registered at 2009-03-23 23:12:20	2009-05-22 05:59:59 - Re: Is the DTG calculation correct
	I understand. However, checking with the great circle tool suggests that the DTG for boats above the rum line is incorrect. eg STU131270 is reading around 917nm to go but the great circle tool suggests the true distance is about 100 nm less.
Posted by jakob Posts 364 Registered at 2007-09-04 10:05:30	2009-05-22 06:42:53 - Re: Is the DTG calculation correct
	DTG-calcs over long ranges when rounding of waypoints are involved are tricky. Just be cool and things will sort out as you get closer, I promise. ...one of the guys behind the game...
Posted by Incognito Posts 183 Registered at 2008-12-06 13:43:52	2009-05-22 07:34:48 - Re: Is the DTG calculation correct
	Hi SOLer's, I have just opened a similar thread. Sorry to repost here. Jakob, I do not want to be mean, but you seem to be in denial. According to SOL, at 7:00 UCT, I was ranked 86th with more than 674 NM to go. In brainaid's ranking however (http://sol.brainaid.de/pub/ranking-145.html), I was ranked 14th with 637 NM to go. Quite a difference! And when I use the pliers or the pointer to calculate the DTG, I come to a figure similar to brainaid's. We had similar issues in led 5. Personnally, I remain convinced that there is an error in the formula used to calculate the DTG in SOL's ranking. It would be nice to fix that sometime. Regards, Francois on Incognito

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