NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Interpolation of Meridional Part Table
From: Brad Morris
Date: 2009 Mar 24, 17:00 -0400
From: Brad Morris
Date: 2009 Mar 24, 17:00 -0400
The constant 7915.704468 may be wrong. That's from Bowditch, 1849. Sorry about that. The technique is correct however. Best Regards Brad -----Original Message----- From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Brad Morris Sent: Tuesday, March 24, 2009 4:57 PM To: NavList@fer3.com Subject: [NavList 7756] RE: Interpolation of Meridional Part Table = LOG(TAN(RADIANS(Latitude/2+45)))*7915.704468 Best Regards Brad -----Original Message----- From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of NavList@aol.com Sent: Tuesday, March 24, 2009 3:42 PM To: NavList@fer3.com Subject: [NavList 7754] Interpolation of Meridional Part Table Anyone, I am looking at a sample problem in section 505 of the 1972 Dutton's. It says that the latitude of Cape Flattery Light is 48d23.5' and says that the meridional parts (m) for that latitude are (is?) 3309.2. Using an on-line versuion of Bowditch Table 6, I located 48 deg latitude and went down the minutes column to 23' to find m=3308.8, and to 24' to find m=3310.3. A linear interpolation would put 48d23.5' at 1/2 the difference, or 3309.55 (round up or down to taste), and one would then have m=3309.5 or 3309.6. I recognize that a linear interpolation doesn't really fit the facts as far as the way meridional parts change; so is there a technique I shold know about that would have given me the result Dutton's got, 3309.2? That is, how did they do that? -John Parsons --------------------------------------- [Sent from archive by: jkp-AT-obec.com] "Confidentiality and Privilege Notice The information transmitted by this electronic mail (and any attachments) is being sent by or on behalf of Tactronics; it is intended for the exclusive use of the addressee named above and may constitute information that is privileged or confidential or otherwise legally exempt from disclosure. If you are not the addressee or an employee or agent responsible for delivering this message to same, you are not authorized to retain, read, copy or disseminate this electronic mail (or any attachments) or any part thereof. If you have received this electronic mail (and any attachments) in error, please call us immediately and send written confirmation that same has been deleted from your system. Thank you." "Confidentiality and Privilege Notice The information transmitted by this electronic mail (and any attachments) is being sent by or on behalf of Tactronics; it is intended for the exclusive use of the addressee named above and may constitute information that is privileged or confidential or otherwise legally exempt from disclosure. If you are not the addressee or an employee or agent responsible for delivering this message to same, you are not authorized to retain, read, copy or disseminate this electronic mail (or any attachments) or any part thereof. If you have received this electronic mail (and any attachments) in error, please call us immediately and send written confirmation that same has been deleted from your system. Thank you." --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
