Equations for the elevated horizon were derived using spherical trigonometry
by Mark Takken, a 10th grader in 2020 at North Salem Schools, NY.
Define the angles
l latitude
e elevation above geometric horizon
x right ascension in deg
y declination.
Then
y(x,e,l) = 90 - a + b, if x < 90 or x > 270
= 90 - a - b, if 90 ≤ x ≤ 270
with
a = arccos[sin(e)/cos(h)]
b = arccos[sin(l)/cos(h)]
h = arcsin[sin(x)cos(l)]
This is graphed at desmos.com/calculator/vtgikoccnz
For further information contact Mark
June, 2020