NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Raw data for bubble
From: Bill B
Date: 2007 Mar 10, 18:41 -0500
From: Bill B
Date: 2007 Mar 10, 18:41 -0500
Peter Wrote > This is a new method for me. I calculate the 'Change of Altitude in 5 > Minutes of Time' as a function of azimuth and latitude. The main thing > is to end up with the actual (apparent) rise or fall as a line, used > to compare the sights made against. They are plotted on graph paper, > altitude vertically, time horizontally. If the sights were perfect > their slope would be parallel to the calculated slope. The extent that > they do not fit that slope is an indication of error, but only of > random error. Does this look like the method you use to calculate slope? Delta H (rate of change in arc minutes) per minute of time (divide by 60 for degrees) Delta H = 15 * cosine latitude * sine azimuth (or its supplement) Bill --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---