NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Longhand Sight Reduction
From: Greg Rudzinski
Date: 2014 Nov 8, 18:04 -0800
From: Greg Rudzinski
Date: 2014 Nov 8, 18:04 -0800
Hanno,
Hc is equal to the calculated altitude from an assumed position that can be directly compared to the observed altitude from the sextant as measured from the natural horizon to the body. I wouldn't be messing around with this basic measurement.
Greg Rudzinski
From: Hanno Ix
Date: 2014 Nov 8, 14:34 -0800
Greg,
thank you for the more detailed explanation.
Whoa, and even a Bygrave aficionado - Frank - seems to melt.
In a way, I am one myself! I love slide rules and I admire
Bygrave's and G. LaPooks's inventions.
I am not a sailor but here is the question I have not resolved:
Why, just why, would anyone want to stick with this Hc thing?
I presume when doing great circle sailing one calculates distances
between waypoints referring to locations on Earth's surface.
These would be w2w or s2w, so to speak. I also presume one
does perhaps even more w2w's or s2w's than s2s's, no?
Seen this way, the sws refers to just another surface point
the distance to which, amongst others, is important to the sailor.
Hc costs a precious EXTRA arithmetic step to find. Please,
what is so specific, advantageous, enlightening, important about it.
If sailors are indeed that practical a lot why would they cling to it?
Well, they are also said to be rather superstitious, right? :)
H
