NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Cocked hats, again.
From: Peter Fogg
Date: 2007 Mar 21, 07:19 +1100
From: Peter Fogg
Date: 2007 Mar 21, 07:19 +1100
Nicol�s wrote: > The standard deviation is only predicting 68% of the error (assuming it > is Gaussian). So if the standard deviation is for instance 20 arcseconds > it only means that there is a 68% chance (or 68.27% to be more precise) Or about 70% to be imprecise! > that the observation is within 20 arcseconds of the actual position. In > order to get 95% probability you need to multiply the standard deviation > by 2 (or 1.96 to be accurate, 2 will give 95.45%), Again, I kept it simple at about 90% Nicol�s, thanks for implicitly confirming my general idea: that by constructing these shadow LOPs the larger shape can offer an overwhelmingly large chance of containing the position, rather than the alleged 25% chance offered by the original LOPs. The other general idea I am hoping to show is that the position is overwhelmingly likely to lie close to the LOPs; each LOP is an approximation of the position. --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
