NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: False Horizons
From: Peter Fogg
Date: 2005 Aug 29, 03:34 +1000
From: Peter Fogg
Date: 2005 Aug 29, 03:34 +1000
Hi Jackie Yes there is. There are also tables, so once you know the distance to the land 'short of the horizon' you can look up a correction factor to be added to the dip correction. The dip adjusts for the height of the observer above the horizon, the other for the point where the sea meets the land short of the horizon. From a small boat the horizon is only about 3 nautical miles away so if the land is further than this no correction is needed. Where to find this table? There is a bible of navigation known as Bowditch. Its available online, and someone else may know the chapter, so you can download at least that part. ________________________________________ From: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM] On Behalf Of jferrari Sent: Monday, 29 August 2005 1:16 AM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: False Horizons I'm new to the list and a relative beginner at practical navigation so I hope my question isn't too elementary. Recently I took a noon sight but the horizon was cut short by a spit of land. I took it anyway as I was curious to see how far out my LOP would be. It was about 1nm out. I wondered could anyone tell me if there is a formula relating the distance that the false horizon is from the real horizon for any give height of eye, and the error incurred in the LOP. Thanks Jackie Ferrari