# NavList:

## A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

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Re: Quartz article: reinstating celestial...
From: Stan K
Date: 2015 Oct 21, 18:44 -0400
FWIW, Celestial Tools lets you check you sight reductions by the Law of Cosines, NASR (NAO Concise), 249, 229, 211 (original and compact), 214, 208, and S-Table (Pepperday and Farley versions).  Intended to help someone learning any of these methods.

Stan

-----Original Message-----
To: slk1000 <slk1000---.com>
Sent: Wed, Oct 21, 2015 6:22 pm
Subject: [NavList] Re: Quartz article: reinstating celestial...

And excellent points from you too Lu.

I want to focus a bit on your comments about the organics of pre-calculator sight reduction and awareness of one’s surroundings.

This is absolutely true and it also extends to the arithmetic involved in sight reduction. By way of example, just for fun, I always reduce a few of my sights using the basic spherical trig formulas and a set of tables with logarithms and trig functions. After a bit of trial and error (as in figuring out how to manage logarithms of negative trig functions), I came up with a nice, neat system.  It has reached a point where I can “feel” if a number or result is just way off the mark. When I say “feel” I am not referring to some telepathic, hocus-pocus new-age thing. I mean that after reducing hundreds of sights and sub-consciously gaining an understanding of mathematical patterns, I can almost always detect errors before spitting out the final answer.  As in “no….that interim number is not right…..I need to go back and check my math or the entry argument”…Something along those lines.

This is not the case for electronic methods such as plugging numbers into a calculator and waiting for an answer.

All of which is to say that while I am still a proponent of electronic calculators, I firmly believe that one should be proficient with paper tables and with the multi-step hand-written process involved in reducing a sight. And further, I believe that HO 240 and HO 211 are the best emergency methods.

Does this make any sense?

Robert

From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Lu Abel
Sent: October-21-15 1:07 PM
To: enoid{at}northwestel.net
Subject: [NavList] Re: Quartz article: reinstating celestial...

Excellent insights as usual, Frank.

If it wasn't apparent from my inquiry about the sight reduction methods that would be used for the USNA course I, too, was wondering what sort of scenario would lead to a practical need for celestial.

For example, in a reply to my post Robert Eno suggested that the midshipmen wold be doing LOC reductions using a scientific calculator.    But if I look at the guts of a calculator vs a GPS set, they're identical -- a battery, a keyboard, a display, and a chip that provides the functionality.  There's no real difference except the functionality embedded in the chip and I can imagine no scenario where only GPS chips are fried.

But there's something organic about pre-GPS navigation where awareness of one's surroundings (whether on shore or in the sky) and use of them is the way one obtains a position.  Not just some numbers on some electronic display, God-only-knows-how-they-got-there.

So, yeah, tradition and awareness -- not necessarily practical needs -- are very likely the motivation for the resumption of teaching Celestial at the US Naval Academy.

Lu

To: luabel{at}ymail.com
Sent: Tuesday, October 20, 2015 6:52 PM
Subject: [NavList] Re: Quartz article: reinstating celestial...

Dave Pike, you wrote:
"On celestial being a back-up for loss of GNSS. Unless the USN has a device that can guarantee clear skies at all times, celestial is a pretty unreliable back-up. This leads me back to my original suggestion that this is as much to do with maintaining standards, engendering confidence in tyro navigating officers, and inculcating a strong sense of the traditions of the USN from John Barry and John Paul Jones onwards as with GNSS loss. The obvious short-term replacement for temporary loss of GNSS is SINS or eLoran, if available, and if all else fails, there’s dead-reckoning."
I worry that some folks are reading too much into the tea leaves on this story (not here, but particularly in other media coverage). It's just one school, and it's a navigation education program with limited aims. This news tells us next to nothing about navigational practice.
Frank Reed

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