A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: No Celestial Love in ECDIS
From: Greg Rudzinski
Date: 2018 Mar 11, 16:09 -0700
A time sight longitude by formula (or Morelli tables) is good enough if meridian angles are greater than 30°. Not too hard to do by trig calculator and of course no azimuth to worry about but requires a reasonably good DR knowledge of latitude. Ex-meridians are generally good for meridian angles less than 10°. Combine the time sight and ex-meridian for a fix with no need for a plot. Old school though.
From: Jeremy C
Date: 2018 Mar 11, 15:23 -0700
I think you may be onto something Greg, although much slower than an integrated machine. Using calculators/software with the DR as the AP, and making a Mariner's Marker on that point and then a series of range and bearings for each body.
I seem to remember Longitude by Chromometer/Time sights were fairly limited by the body needing to be bearing nearly E/W no? It's been a long time since I've done one.
In any case, I will see if I can give feedback to the company. I don't know if I'll be able to experiment for awhile however.
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