NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: refraction
From: Guy Schwartz
Date: 2007 Jan 4, 19:31 -0800
From: Guy Schwartz
Date: 2007 Jan 4, 19:31 -0800
Lets take the sun for example, how would one know if they were viewing it with or without refraction to start the analysis? ----- Original Message ----- From: "Lu Abel"To: Sent: Thursday, January 04, 2007 7:11 PM Subject: [NavList 1977] Re: refraction > > Not much different than measuring bending of the stick, Guy, except with a > bit of patience required. > > If I track the rising or setting of a body, I should see a uniform rate of > motion in the sky as long as refraction is insignificant. Once it becomes > significant, however, the rate should change. > > I could, for example, calculate the expected time a body would disappear > below the horizon based on its motion through the sky. But I would > observe it to set later. The time of observed setting would lead me to a > value for refraction, ie, the amount the body is below the horizon and > therefore the amount of refraction. > > Measurement of factors such a pressure, humidity, and temperature could > then be used to refine the parameters. > > Lu Abel > > Guy Schwartz wrote: >> Inserting a 4 foot stick half way into a big tank of water at a 45 degree >> angle, the refraction can be measured or closely approximated. >> How were the refraction adjustments initially calculated for the >> atmosphere? >> What was the methodology used? I don't think it was as easy as the stick >> in the water method? >> Thank you. >> Guy >> > > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.432 / Virus Database: 268.16.5/616 - Release Date: 1/4/2007 > 1:34 PM > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---