A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2015 Nov 27, 14:07 -0800
Dave, the attachment is relevant for the 180E/W issue. Peter Hakel
Thank you Peter. My early morning dozing didn’t include MOD only nested IF s. See below. Actually, my dozing came up with sequential IF s, but there turned out to be no such thing. I had to Google ‘More than one IF in Excel’ to get the correct syntax. The complete spreadsheet just needs tidying up now. Wrt MOD, I can’t see how -180/360 gives a remainder of 179.
Nevertheless, isn’t digital wonderful. The analogue GPI 6 in the Vulcan was very accurate but incredibly slow to reset. On the rare occasions when the guys had to cross 180W, they carried a second GPI 6 set up in workshops to 180E. They quickly unscrewed the one that had got up to 180W and screwed in the one set to 180E, what you might call an analogue solution. DaveP