For a sunrise equation, celestial nav's angular height formula can be used. Replace the unknown Hc with the expected Ho which will be (Hs ≡ 0° 00.0' plus) the sum of corrections for dip (-.98' × the square root of the eye height in feet), semidiameter(about -16'), and atmospheric refraction. The refraction will be about -34.7' - (.18' × the square root of the height of the eye in feet). Rearrange the formula to solve for LHA or t (angle). [Draw a diagram with the nearer pole at the center!] Summing that angle and the observer's longitude tells the Sun's GHA. An Almanac gives the Sun's GHA at intervals, so interpolate for the approximate instant of sunrise.
Beautiful, thanks!
You are great sir
Thank you so much!
thanks sir
Awesome video. Can you give the derivation of sunrise equation and solar declination angle?
For a sunrise equation, celestial nav's angular height formula can be used. Replace the unknown Hc with the expected Ho which will be (Hs ≡ 0° 00.0' plus) the sum of corrections for dip (-.98' × the square root of the eye height in feet), semidiameter(about -16'), and atmospheric refraction. The refraction will be about -34.7' - (.18' × the square root of the height of the eye in feet).
Rearrange the formula to solve for LHA or t (angle). [Draw a diagram with the nearer pole at the center!] Summing that angle and the observer's longitude tells the Sun's GHA. An Almanac gives the Sun's GHA at intervals, so interpolate for the approximate instant of sunrise.
Amazing
Is there something similar for stereographic projection?
Thanks
There is a faster way using vectors, dot cross products and Binet-Cauchy identity
nifty