NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Anomalous dip. was: [NAV-L] Testing pocket sextant.
From: Bill B
Date: 2006 Jun 16, 17:20 -0400
From: Bill B
Date: 2006 Jun 16, 17:20 -0400
George > I've just posted a meassage, in the hope of reducing > misunderstandings, in which was the paragraph-... large snip Thank you George, but I did get your meaning, hot, warm, cool, cold the first time;-) While it has been discussed on a plane too high for me to comprehend in the past, your latter explanations were clear and understandable to this layperson. Especially once you did away with ambiguous (to me) use of signs. You also defined "lapse rate, a missing key for me. George et al Now that I have the basic concept, what happens on a larger scale? We could use Frank's beach shots as an example (Indiana to Chicago, approx. 22 nm). Assume a thermal inversion as Frank stated. What will that do to the horizon relative to a horizon with well-mixed air (shift it up or down) and what will it do to building tops around 1100-1500 feet above water level (raise or lower them)? The problem I was having using the current Bowditch Table 15 formula was that the distance kept falling short, meaning if the T15 constants are correct, the angle measured was too large. Therefore if the horizon was shifted up, the building tops must have been shifted up to a greater extent. I understand the problem as stated may be too complex for a simple answer, but try a if-then. I also strongly suspect another problem area is the Bowditch constants. Thanks Bill