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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Averaging lunars: was Lunars with SNO-T
From: Herbert Prinz
Date: 2004 Nov 2, 02:24 -0500
From: Herbert Prinz
Date: 2004 Nov 2, 02:24 -0500
Dear Alexandre, In a message from 2004-10-09 I had claimed that it is mathematically wrong to average the observed altitudes before feeding them into the sight reduction process, because the only rigorously correct method minimizes the sum of the squares of the altitude residuals (i.e. observed altitude minus computed altitude). You had asked for the references that I made to articles discussing relevant LSQ algorithms in "Navigation: Journal of The Institute of Navigation" C. DeWit, Optimal Estimation of a Multi-Star Fix, Vol. 21, No 4, 1974-76 Robert W. Severance, Overdetermined Celestial Fix by Iteration, Vol. 36, No 4, Winter 1989-90 Thomas R. Metcalf, Frederic T. Metcalf, On the Overdetermined Celestial Fix, Vol. 38, No. 1, Spring 1991 There are probably many more, but these are the references in have noted down. Regards Herbert Prinz