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Re: Exercise #14 Multi-Moon LOP's
From: Mike Burkes
Date: 2008 Nov 17, 18:03 -0800
From: Mike Burkes
Date: 2008 Nov 17, 18:03 -0800
Hi Peter, pretty close I got 14d 15.4N, 142d 53.3E. Mike Burkes On Nov 16, 1:19�am, "Peter Fogg"wrote: > Federico you asked, on 8 Aug last: "Any comments?" > > Basically agree. �Using all of the sights I derive, at the time of the > first, a probable position of: > N14d 15.3' �E142d 53.2'. �Have allowed for the ship's movement while the > upper limb of the moon is being observed. � As Greg Rudzinski points out, > the ship is steaming at 080d, while the position line extends towards 069d; > fairly similar. > > Have plotted these sights and compared them with the calculated slope. �They > are evidently very consistently good observations, showing little spread. > Since the apparent movement of the moon (or any celestial body) as it > rises/falls is an arc, extending the time-spread of the multiple sights > beyond about 5 minutes, as here, could lead to those at either end being > less reliable. > > Adopting 19h 08m 00s and 65d 54' leads to an azimuth of 159.1d and an > intercept of T0.6, which may be a slight improvement on the sight taken at > close to that time, #4: 19h 08m 06s, Hs 65d 55.0' ? �At any rate, plotting > them reveals that there are none (excepting perhaps those at either end, for > the reason above) which need be discarded. �In this case an average should > give a good result. > > Jeremy posted the problem in NavList 5416 on 13 Jun 08; mind his corrections > which followed soon after. > > On Fri, Aug 8, 2008 at 9:34 PM, Federico Rossi wrote: > > > > > �Hello everybody, > > > I was browsing through the exercises that Jeremy kindly posted on the list > > back in June. Today I was working out exercise 14 Multi-moon LOP's and I've > > seen there was no solution posted (if I'm not wrong), so here's mine. > > > I've averaged the sights and obtained a Hs of 65 deg 59,8' at 09 09 14 UTC > > (or 19 09 14 ZT). This yields to a calculated altitude of 65 deg 55,5' (I > > use the haversine method and Norie's tables 'cause I like working the old > > way) and to an intercept of 1.3 NM forward. The azimut is 160 deg. Moving > > back the LOP to 19 00 00 ZT and assuming the intersection between this LOP > > and the course made good as the most probable position I got a fix at 14 deg > > 17,0' N 142 deg 58,5' E. > > > Any comments? > > > Federico > > > > �Slope.pdf > 785KViewDownload- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To unsubscribe, email NavList-unsubscribe@fer3.com -~----------~----~----~----~------~----~------~--~---