NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Latitude and longitude around noon
From: Francis Upchurch
Date: 2017 Mar 4, 15:26 -0000
From: Francis Upchurch
Date: 2017 Mar 4, 15:26 -0000
Apologies, LAN 16 59 16 from graph and equal altitudes gives Long 71*48.3'.My error. Francis -----Original Message----- From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Francis Upchurch Sent: 03 March 2017 17:49 To: francis@pharmout.co.uk Subject: [NavList] Re: Latitude and longitude around noon I tried 3 methods. 1) Quick and dirty. Assume noon alt 41deg30',Ho 41*36'36'', ZD 48*23', Lat 41*26.4'. EoT=+12'5''.LAN Greenwich=12.12.5. = 4.48.35 time difference.=72* 8.7' W 2) Slow and dirty. Graph. LAN 16 59 16 gives Long 72*2' W 3)equal altitudes gave same result as 2). Did not know to correct for the 1knot northing of the sun. Please explain Frank. Best wishes Francis -----Original Message----- From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Frank Reed Sent: 02 March 2017 21:34 To: francis{at}pharmout.co.uk Subject: [NavList] Latitude and longitude around noon Four hours ago I took a series of Sun sights around local noon. Here's the raw data: 16:35:30, 41° 13.0' 16:40:55, 41° 20.9' 16:48:02, 41° 25.8' 16:55:39, 41° 28.8' 17:00:38, 41° 30.0' 17:02:46, 41° 28.7' 17:06:22, 41° 27.3' 17:12:25, 41° 23.3' 17:19:18, 41° 15.2' 17:23:19, 41° 09.0' Times are UT. Altitudes are Sun LL, as usual. Height of eye 24 feet. Index error was about 3.8' on arc. Can you determine my latitude and longitude from these sights? How many different ways can you come up with to get a fix from these observations? Incidentally, my "northing" speed was zero, but the Sun is northbound at about 1 knot this time of year. I was able to shoot the Moon and Venus, too, so there were ample opportunities to get a celestial fix today. The weather was chilly and blustery. Great waves! See photos. Frank Reed [plain text auto-generated] ---------------------------------------------------------------- NavList message boards and member settings: http://fer3.com/NavList Members may optionally receive posts by email. To cancel email delivery, send a message to NoMail[at]fer3.com ---------------------------------------------------------------- ---------------------------------------------------------------- Attached File: http://fer3.com/arc/imgx/wind-and-waves1.jpg Attached File: http://fer3.com/arc/imgx/wind-and-waves2.jpg : http://fer3.com/arc/m2.aspx/Latitude-longitude-around-noon-FrankReed-mar-2017-g38484 : http://fer3.com/arc/m2.aspx/Latitude-longitude-around-noon-Upchurch-mar-2017-g38505