NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Interpolation to latitude
From: George Huxtable
Date: 2009 Nov 10, 23:30 -0000
From: George Huxtable
Date: 2009 Nov 10, 23:30 -0000
Joe Schultz wrote, in [10549] "I think you may be confused as to where LMT is, regarding this type of exercise. LMT means at the local zone meridian longitude..." I'm a bit puzzled by that. In what way does the zone enter into Local Mean Time? George. contact George Huxtable, at george@hux.me.uk or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ----- Original Message ----- From:To: Sent: Tuesday, November 10, 2009 10:51 PM Subject: [NavList 10549] Re: Interpolation to latitude Hi Inuik, I think you may be confused as to where LMT is, regarding this type of exercise. LMT means at the local zone meridian longitude and the DR latitude. Sometimes a picture helps - see the attached inuik.gif. The time suffix "P" refers to the W45d time zone, sometimes written as "P-3" which means "papa zone is minus 3hr from GMT." Different letters for different time zones; GMT = "Z" and is the zero longitude time zone, pronounced "zulu." Notice how I did the calculations in the local "P" time zone, then converted to GMT. You can start your computation with LOW LAT TIME = 0447 "Z". Then your LON CORRN would be 3h 21m, since you started the computation in "Z" time (zero longitude). Try it both ways, then stick with whatever floats your boat. You do want to apply the LAT CORRN first. The method will then be consistent with the moon event computation method, which needs a "change in LMT" calculation as an entering argument for the LON CORRN. But first things first. Be sure you understand the sun event computations before trying the moon events. Joe --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---