High telescope searching...

old_tex · 01-16-09, 07:06 PM

The formula for Line of Sight is:
distance = Sqrt(2*R*h+(h^2)), where:
R = Radius of the Earth
h = Eye Height

Note: Use the same units for all variables (km, nm, yds, m, etc)

Since the Earth is a Oblate Spheroid (a pear), the diameter and thus the radius varies according to location. The Earth's approximate radius is:
6357 ~ 6378 km
3950 ~ 3963 miles, or 8000067 ~ 8026396 yds (nm = 6076)

Therefore: Using the values in the tables listed in this thread, an Eye Height of 79 ft yields a distance of 20,610 yds.
By the formula, where the Earth's Radius is 8000067 yds and the Eye Height is 26 yds (79/3), the distance to the horizon is 20,527 yds.

That's pretty close!

Old_tex

01-16-09, 07:06 PM	#8
old_tex Gunner Join Date: Sep 2008 Location: New Mexico Posts: 94 Downloads: 12 Uploads: 0	LOS Formula The formula for Line of Sight is: distance = Sqrt(2Rh+(h^2)), where: R = Radius of the Earth h = Eye Height Note: Use the same units for all variables (km, nm, yds, m, etc) Since the Earth is a Oblate Spheroid (a pear), the diameter and thus the radius varies according to location. The Earth's approximate radius is: 6357 ~ 6378 km 3950 ~ 3963 miles, or 8000067 ~ 8026396 yds (nm = 6076) Therefore: Using the values in the tables listed in this thread, an Eye Height of 79 ft yields a distance of 20,610 yds. By the formula, where the Earth's Radius is 8000067 yds and the Eye Height is 26 yds (79/3), the distance to the horizon is 20,527 yds. That's pretty close! Old_tex