Sight Reduction Calculator.51, copyright logiciel tirage au sort nom Henning Umland, geographic position of body: Assumed position: Greenwich hour angle '.
Your observed altitude (steps 1-3 below) is compared to a calculated altitude (steps 4-5) calculated to be what altitude you would get if you were actually at the position you chose as your assumed position.
It is unfortunately out of print, but you can usually find it at libraries.Henning Umland N 53 20' 34' E 9 52' 00' Check this web site for updated versions:.You can also make one by using a flat pie pan filled with water, or preferably oil.Be sure to read the instructions; you have divide the angle by two when using an artificial horizon.Or purchase the 2102-D Star Finder from Starpath.This book is short and to the point, and many people swear.Scroll through the chapters and look them over, and check out Chapter 2 on how to make all the various sextant corrections.Enter the altitude correction parameters, and hit the Reduce sight button.There are also PDF worksheets available on the Reader Page sent in by reader Harold Arsem.Here is their archive site.Neither of those has all the information you need.In this case, entering a semidiameter is not required (will be ignored).The program does the rest.The semidiameter of the moon is internally computed from the horizontal parallax if the latter exceeds 50'.If you purchase one, make sure the Almanac looks like one of these (I have a commercial edition that is slightly different, but still with a blue cover).For shooting stars, a Star-Finder would also help; you can buy the 2102-D, a kind of modern planispheric astrolabe, and there are some online, such as once again, and what would we do without him?There is a great online tutorial by Al Placette that walks you through much of what is needed for reducing a sight.O.
Upper limbLower limbCenter, altitude correction parameters: Results: Index error* observed altitude height of eye m ft, computed altitude '.
These are found in tutorials; see, for example, Chapter.
Asnav, designed by a seaman for seamen.