NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Talking to "Official" Authorities
From: Paul Hirose
Date: 2012 Apr 11, 23:38 -0700
From: Paul Hirose
Date: 2012 Apr 11, 23:38 -0700
Antoine Couëtte wrote: > You will find here-enclosed a translation I just performed to your intention of the Note I sent to Bureau des Longitudes IMCCE in March 2011. It's time to go to bed here in California, but my quick explanation for your anomaly: I think the IMCCE is using the IAU 1976 precession model. I wrote a small program to calculate the geometric geocentric ecliptical longitude and latitude of the Sun with respect to the mean equinox of date. DE406 ephemeris. IAU 1976 precession from SOFA routine iau_PMAT76 and mean obliquity from iau_OBL80. Dates are Julian calendar. -95 May 22 04:50 TT 57°03'30.2" -0°00'01.8" -95 Jun 04 04:50 TT 69°26'04.5" -0°00'02.9" -95 Jun 18 04:50 TT 82°45'53.8" -0°00'01.6" To the accuracy of my table, these are identical to the values in part 1a of your attachment. Tomorrow I will give a more complete answer. --
