NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Revisiting A thought question
From: Bill B
Date: 2007 Jan 01, 14:32 -0500
From: Bill B
Date: 2007 Jan 01, 14:32 -0500
Guy wrote: "Having just enjoyed a wonderful weekend at Lake Tahoe elevation of 6225 ft. I was thinking about what my height of eye would be if I were taking sites at this elevation? Not that I would be lost on the Lake it is 22 miles long by 12 miles wide." It struck me in the shower this AM I may have missed one point that had been discussed a year or two ago. That being reduced refraction in the thinner air. I don't recall the consensus--if there was one. The broadcast barometric pressure will be adjusted to sea level. At 6225 feet multiply the broadcast BP by .823 for local BP. The adjusted BP will be off the almanac table, but gives you a starting point. BTW, the adjustment was calculated with a formula given by Frank. Adjustment factor is natural antilog of (elevation in feet / -32000). Hope I said that right. Somewhere I may have a formula for adjusting refraction for pressure, but hope another list member has it at the tip of their tongue. Bill --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
