NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: A lesson in a photo
From: David Pike
Date: 2016 Aug 28, 13:15 -0700
From: David Pike
Date: 2016 Aug 28, 13:15 -0700
I saw that effect a couple of times from TIKI on a flat calm sunny day in the Baltic summer. I just assumed it was the wake of a ship that had travelled for miles or the Baltic equivalent of the Loch Ness Monster.
Parachute diameter = 115ft = 18mm on my print
Capsule = 18mm above horizon on my print = 115ft
Ripple = 1mm on my print. Lets assume it's half a minute of arc
Angle of capsule above horizon = 18 x ½ = 9’ = 0.15
Tan0.15 = Perp/Base = 115/Range in ft.
So Range = 115/tan0.15 x 5280 = 8.3 statute miles. The SpaceX Dragon website says about ten miles. Maybe I’ll stop looking for that magic equation. DaveP
