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Re: Summary of Bowditch Table 15
From: Bill B
Date: 2005 Jan 26, 18:19 -0500
From: Bill B
Date: 2005 Jan 26, 18:19 -0500
Jim Regarding the table 15 formula I wrote: > How the formula works I leave to the math whizzes. Clues are we see the > square root of H-h/0.7349, which would equal H-h * 1.36. Pretty close to > geographical range and horizon constant of 1.169 or 1.17. We also see > tangents of the angle, and they are divided by 0.0002419. The same as > multiplying by approx. 4134. That number looks suspiciously close to the > Earth's radius. We also play with the affect of the "hump" expressed as an > angle by subtracting dip. But there are no old bold empiricists, so I'll > quit there ;-) Giving it more thought, the tangent is the ratio between the height of object and distance (opposite over adjacent). Perhaps the x/0.0002419 or x * 4134 (a nautical mile in feet adjusted for refraction) converts the answer to nautical miles? Bill