NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Celestial Calculator Comparisons
From: Dan Allen
Date: 2000 Mar 10, 10:13 AM
From: Dan Allen
Date: 2000 Mar 10, 10:13 AM
There is a spectrum of celestial nav possibilities: a) GPS - push a button, get an answer - easiest thing going, but depends upon 24 satellites above, along with a support infrastructure on the ground. Fix in 15 seconds. b) Sextant & calculator - not as handy, but fully self-contained. The calculator needs power, but if you have a solar battery charger and 3 AAA nicads, you could run an HP-48 for a long time... Fix in a few minutes. c) Sextant & slide rule or HO 249 or paper - no energy concerns at all; works in all climates and temperatures, fully self-contained, and gives the navigator something to really sink his teeth into. Fix in 15-30 minutes. I believe that we need to be skilled in all three. One solution that has helped take the drudgery out of the last option for me is to write my own celestial nav software on my HP-48GX. This has kept the principles and concepts clear in my mind so that I can play with the basic formulas and feel comfortable with them in case I did need to go the option C route above. Dan Allen danallen@nwlink.com Navigate | Calculate | Communicate > Set Sail! -----Original Message----- From Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Joe Shields Sent: Friday, March 10, 2000 8:01 AM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Re: Celestial Calculator Comparisons As a landlocked armchair navigator who dreams of one day moving beyond my little 1 nm wide (at its widest part) man-made lake and out into blue water where I could do celestial nav. for real, I may be naive, but I am confused by all this concern over celestial calculators. Wouldn't regular use of an 'electronic' celestial calculator defeat the whole purpose of celestial navigation -- a reliable alternative/backup to 'electronics'. Doing sight reduction by hand (in both my opinion and the opinion of the ASA Instructor who certified me) is a volatile skill that needs to be practiced regularly to be reliable. What you don't use, you lose... which could be everything from your copy of HO 249 (or whatever) to doing accurate mental arithmetic. Is my thinking wrong that the best discipline is that my daily navigation would consist of doing traditional 'non-electronic' celestial/coastal/DR navigation to arrive at my position and then check it against the GPS. With everything in close agreement, my comfort-level would be such that any 'electronic' outage would not give rise to panic or drastically alter my navigational routine. Or is it more realistic that you are busier than a one-armed paperhanger, and you need all the shortcuts you can get. -- Joe Shields (lat:40 34, long:80 04)