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Re: Are we most likely not where we are?
From: Brian Whatcott
Date: 2002 Apr 15, 09:23 -0500
From: Brian Whatcott
Date: 2002 Apr 15, 09:23 -0500
At 08:27 AM 4/15/02, Bill Murdoch wrote: >In a message dated 4/15/2002 12:06:50 AM Eastern Daylight Time, >hprinz@ATTGLOBAL.NET writes: > > >>The >most probable position (MPP) is, by definition (!), inside the cocked hat. > > >I am not so sure about that. I think it may be true if the errors are >random, but not if they are not. Let's say I have three bodies at 300, >000, and 060 degrees (the horizon is dirty to the south), and a sextant >with an (unknown to me) 5 arcminute error. I reduce my sights, get a nice >small cocked hat and am actually 5 miles to the same side of all three >LOPs. It seems to me that my most probable position is outside the cocked >hat. Now these are non-random errors, but those are the pretty normal (at >least for me). > >Bill Murdoch The argument against, goes like this: If I experience systematic errors that are material, I can compensate for them, in the long run. I am then left with random errors which are reasonably handled with probability ideas, served reasonably well by a cocked hat. If I allow a material systematic error to continue uncompensated, shame on me. Brian W Brian Whatcott Altus OK Eureka!
