NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Just getting started
From: Robert Eno
Date: 2007 Jan 19, 14:42 -0500
From: Robert Eno
Date: 2007 Jan 19, 14:42 -0500
I cannot prove this as the person who told me passed away some years ago, however, he was in the military and therefore presumably would have had some insight into the matter. According to my late friend, HO 229 was developed to provide a tabular and manual method of calculating great circle distances and headings of long-range targets. As I said, I can only take the man at his word, and he was a highly reliable and sober source. Robert ----- Original Message ----- From: "Royer, Doug"Date: Friday, January 19, 2007 1:51 pm Subject: [NavList 2095] Re: Just getting started > > > > > For tables either H.O 249 or H.O. 229 or H.O. 214 are all very > similar > and 249 is the most convenient but only has a precision of one > minute of > > arc which is an accuracy on one nautical mile which is realistic > on a > small boat. If you want higher precision, especially for practice > shots > while on shore, then 229 or 214 will do. 214 is out of print but > I > think its arrangements of the tables is more convenient than in 229. > > BTW, does anybody know why they switched from the 214 format to > the 229 > format so you cant just do a round of sight using only one page as > you > could do with 214 but have to chase all over for the LHAs? > > My understanding for the change in format from HO-214 to HO-229 > was for > ease/speed of tabular reduction with about the same level of > precision.That may be correct. HO-229 does eliminate a step or two > compared with > HO-214. But then kind of requires the addition of a step when > computingthe double 2nd difference. > > To expand on this further for the new guy's benefit: > I, personally, like using the old HO-214. > HO-249 vol. #1 is quick and easy to use but limits a person to using > only the listed stars. Sometimes those listed stars can't be used > because of local conditions but other, unlisted, bodies that may be > useable can't be included for reduction because there is no data > listedfor them. > HO-249 Vols. #2 and 3 are arranged in the same format as are HO- > 229 and > does away with this limitation. > > If you want a short tabular method H.O. 208 is my preference. > > Good method. My preference is in using HO-211. It consists of 28 pages > of data in one volume which covers it all from anywhere. Easy to > use and > quick for obtaining passable results with no limitations on which > bodiesmay be used. For those minimalists in small vessels there is > a 9 page > volume of the same method. > > You can find many of these books on ebay. > > Or one may download a copy of both HO-208 and HO-211: > > http://www.geocities.com/sadams16/Navigation1.html > > Or the other methods if you desire. I just like having the hardback > volumes of HO-214 thru HO-249 to use but it may not be practical > in a > small vessel or if money is an issue the above link will give you the > volumes. > > > > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---