Re: Were Short methods really Short?
From: Greg Rudzinski
Date: 2016 Aug 3, 14:22 -0700
Short refers to the length of the tables needed to perform sight reduction rather than the length of time it takes to generate a calculated altitude and azimuth. Grading the various SR short tables is up to the needs of the individual navigator. I prefer to use a method which is as error free as possible, simple enough to do without the need of a form, and fits into the sextant box. Pub 208, Weem's Line of Position Book, Pub 211, Ageton Classic, and Hav Doniol will get it done to 1' precision. I suggest learning them all and picking at least two favorites for the sextant box.
P.S. My favorites :Hav Doniol, Ageton Classic, and Pub 208 (all three fit into the sextant box with room to spare).
rom: David C
Date: 2016 Aug 2, 16:22 -0700
For many years I had a passive interest in Nautical Astronomy. I studied the subject and from time to time purchased a second hand book. I formed the impression that reducing sights by the hav-cosine formula and tables such as Norie was difficult/tedious/complicated/took a long time. On the other hand short methods were quick and easy. Having now worked sights by hav cosine/Norie, Ageton and Norie A-K I am not so sure.
In this age of GPS and massive computing power it is difficult to put ourselves in the minds of navigators in the pre-electronic and pre-inspection table eras. Also I am writing this in armchair comfort and safety. However I would like to ask the question "Were short methods any shorter than hav cosine/Norie?"
I took my work forms for hav-cosine and Ageton and stripped out the common elements - HS correction, determination of GMT, t and dec. I then merged the two forms. See the attached pdf.
The pros of Ageton are the small physical size of the tables and the lack of interpolation. The cons (in my opinion) are that there is little if any saving in work and it is probably easier to get confused.
So, in hindsight, were short methods an improvement over the hav-cosine method?