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Re: Exercise #5 Lat/Long near Noon.
From: George Huxtable
Date: 2008 May 31, 16:44 +0100
From: George Huxtable
Date: 2008 May 31, 16:44 +0100
I have confirmed that Jeremy's plot of altitude around noon was not a true plot against time but a sequential plot against sight-number. Because, very near noon, his sights were taken more closely than at other times, it made a slight but significant difference. In an attachment I have replotted his same data as an x-y plot against time, and added it below the first plot, to make any difference apparent. You can see that it now becomes somewhat less flat, near to noon. Of course, the centre point of the resulting curve isn't very different. Ignoring that obviously-duff observation, I would put it at about 15.5 minutes, with an error of about 0.1 minute of time, which would be 1.5 minutes of longitude. Does anyone else claim he can do better? I take Jeremy's claim, that he can do it to 2 seconds, with a grain of salt... George contact George Huxtable at george@huxtable.u-net.com or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
File: 105228.latlong-noon2.xls
